Prepare 2.2.0.dev2. (pantsbuild#11321)

### Internal Changes

* Switch process_executor to structopt ([pantsbuild#11306](pantsbuild#11306))

* [internal] Enable the Toolchain plugin in CI. ([pantsbuild#11264](pantsbuild#11264))

* Include TRAVIS_BUILD_WEB_URL in the environment variables sent to Toolchain. ([pantsbuild#11297](pantsbuild#11297))

[ci skip-rust]

src/python/pants/VERSION

@@ -1 +1 @@
-2.2.0.dev1
+2.2.0.dev2

src/python/pants/notes/2.2.x.md

@@ -9,6 +9,24 @@ https://raw.githubusercontent.com/pantsbuild/setup/2f079cbe4fc6a1d9d87decba51f19
 This release also removes the ability to use `%(pants_bootstrapdir)s` and `%(pants_configdir)s` in
 interpolations in your config file.
 
+## 2.2.0.dev2 (Dec 16, 2020)
+
+### Plugin API Changes
+
+* Upgrade packaging from 20.4 to 20.7 ([#11302](https://github.com/pantsbuild/pants/pull/11302))
+
+* Update default values for run tracker and streaming work unit handlers to more commonly used values. ([#11292](https://github.com/pantsbuild/pants/pull/11292))
+
+### Bug fixes
+
+* Fix filtering of log messages generated in native code. ([#11313](https://github.com/pantsbuild/pants/pull/11313))
+
+* Upgrade to Pex 2.1.24 to fix macOS Big Sur. ([#11312](https://github.com/pantsbuild/pants/pull/11312))
+
+* Clean the graph speculatively, and cancel nodes when interest is lost ([#11308](https://github.com/pantsbuild/pants/pull/11308))
+
+* Implement native Process cache scoping to fix --test-force ([#11291](https://github.com/pantsbuild/pants/pull/11291))
+
 ## 2.2.0.dev1 (Dec 09, 2020)
 
 ### New Features