Remove migration scripts <=0.38 (cosmos#9291)

* Remove migration scripts <=0.38

* Add changelog

* remove more

* remove more stuff

* Fix test

* Relase wording

* Add comment

* Include migratio wording

CHANGELOG.md

@@ -67,6 +67,7 @@ if input key is empty, or input data contains empty key.
   * via `ServiceMsg` TypeURLs (e.g. `message.action='/cosmos.bank.v1beta1.Msg/Send'`) does not work anymore,
   * via legacy `msg.Type()` (e.g. `message.action='send'`) is being deprecated, new `Msg`s won't emit these events.
   * Please use concrete `Msg` TypeURLs instead (e.g. `message.action='/cosmos.bank.v1beta1.MsgSend'`).
+* [\#9291](https://github.com/cosmos/cosmos-sdk/pull/9291) Migration scripts prior to v0.38 have been removed from the CLI `migrate` command. The oldest supported migration is v0.39->v0.42.
 
 ### API Breaking Changes
 

STABLE_RELEASES.md

@@ -4,19 +4,16 @@
 
 Only the following release series are currently supported and receive bug fixes:
 
-The `0.37.x` release series will continue receiving bug fixes until the Cosmos Hub
-migrates to a newer release of the Cosmos-SDK.
+* **0.39 «Launchpad»** will be supported until 6 months after **0.42.0** is published. A fairly strict **bugfix-only** rule applies to pull requests that are requested to be included into a stable point-release.
+* **0.42 «Stargate»** is the latest stable release.
 
-* **0.37** will continue receiving bug fixes until the Cosmos Hub migrates to a newer release series of the Cosmos-SDK.
-* **0.39 «Launchpad»** will be supported until 6 months after **0.40.0** is published. A fairly strict **bugfix-only** rule applies to pull requests that are requested to be included into a stable point-release.
-
-The **0.39 «Launchpad»** release series is maintained in compliance with the **Stable Release Policy** as described in this document.
+The **0.42 «Stargate»** release series is maintained in compliance with the **Stable Release Policy** as described in this document.
 
 ## Stable Release Policy
 
 This policy presently applies *only* to the following release series:
 
-* **0.39 «Launchpad»**
+* **0.42 «Stargate»**
 
 ### Point Releases
 
@@ -48,6 +45,10 @@ priority is to minimise the risk caused by changes that are not strictly require
 be correlated with minimising the size of such changes. As such, the same bug may need to be fixed in different
 ways in stable releases and `master` branch.
 
+### Migrations
+
+To smoothen the update to the latest stable release, the SDK includes a set of CLI commands for managing migrations between SDK versions, under the `migrate` subcommand. Only migration scripts between stable releases are included. For the current release, **0.39 «Launchpad»** and later migrations are supported.
+
 ### What qualifies as a Stable Release Update (SRU)
 
 * **High-impact bugs**
@@ -86,12 +87,12 @@ As rule of thumb, the following changes will **NOT** be automatically accepted i
 
 ## Stable Release Exception - Procedure
 
-1. Check that the bug is either fixed or not reproducible in `master`. It is, in general, not appropriate to release bug fixes for stable releases without first testing them in `master`. Please apply the label [0.39 «Launchpad»](https://github.com/cosmos/cosmos-sdk/labels/0.39%20LTS%20%28Launchpad%29) to the issue.
+1. Check that the bug is either fixed or not reproducible in `master`. It is, in general, not appropriate to release bug fixes for stable releases without first testing them in `master`. Please apply the label [0.42 «Stargate»](https://github.com/cosmos/cosmos-sdk/labels/0.42%20LTS%20%28Stargate%29) to the issue.
 2. Add a comment to the issue and ensure it contains the following information (see the bug template below):
  * **[Impact]** An explanation of the bug on users and justification for backporting the fix to the stable release.
  * A **[Test Case]** section containing detailed instructions on how to reproduce the bug.
  * A **[Regression Potential]** section with a clear assessment on how regressions are most likely to manifest as a result of the pull request that aims to fix the bug in the target stable release.
-3. **Stable Release Managers** will review and discuss the PR. Once *consensus* surrounding the rationale has been reached and the technical review has successfully concluded, the pull request will be merged in the respective point-release target branch (e.g. `release/launchpad/0.39.X` being `X` the Launchpad's upcoming point-release) and the PR included in the point-release's respective milestone (e.g. `0.39.5`).
+3. **Stable Release Managers** will review and discuss the PR. Once *consensus* surrounding the rationale has been reached and the technical review has successfully concluded, the pull request will be merged in the respective point-release target branch (e.g. `release/v0.42.x`) and the PR included in the point-release's respective milestone (e.g. `0.42.5`).
 
 ### Stable Release Exception - Bug template
 
@@ -102,7 +103,7 @@ Brief xplanation of the effects of the bug on users and a justification for back
 
 #### Test Case
 
-Detailed instructions on how to reproduce the bug on Launchpad's most recently published point-release.
+Detailed instructions on how to reproduce the bug on Stargate's most recently published point-release.
 
 #### Regression Potential
 
@@ -124,8 +125,7 @@ Their responsibilites include:
 
 The Stable Release Managers are appointed by the Interchain Foundation.
 
-*Stable Release Managers* for the **0.39 «Launchpad»** release series follow:
+*Stable Release Managers* for the **0.42 «Stargate»** release series follow:
 
 * @alessio - Alessio Treglia
-* @clevinson - Cory Levinson-
-* @ethanfrey - Ethan Frey
+* @clevinson - Cory Levinson

x/auth/legacy/v034/types.go

@@ -1,3 +1,6 @@
+// Package v034 is used for legacy migration scripts. Actual migration scripts
+// for v034 have been removed, but the v039->v042 migration script still
+// references types from this file, so we're keeping it for now.
 // DONTCOVER
 package v034
 

x/auth/legacy/v038/types.go

@@ -1,3 +1,6 @@
+// Package v038 is used for legacy migration scripts. Actual migration scripts
+// for v038 have been removed, but the v039->v042 migration script still
+// references types from this file, so we're keeping it for now.
 package v038
 
 // DONTCOVER