Prepare the 2.16.0rc2 release. (pantsbuild#18986)

src/python/pants/notes/2.16.x.md

@@ -45,6 +45,8 @@ constraints. Instead of relying on this default, explicitly set the
 interpreter minor version if you can, e.g., `interpreter_constraints = ['==3.11.*']`, or at least
 a small number of interpreter minor versions, e.g., `interpreter_constraints = ['>=3.10,<3.12']`.
 
+- The special Python "tool lockfile" functionality is deprecated. Repos can now use regular "user lockfiles" to provide custom versions of tools.
+
 #### Shell command improvements and support for ad-hoc tools
 
 The Shell backend along with the new `pants.backend.experimental.adhoc` backend have received a number of improvements so that
@@ -154,6 +156,56 @@ The `ToolCustomLockfile` and `ToolDefaultLockfile` classes [have been removed](h
 
 ----
 
+## 2.16.0rc2 (May 11, 2023)
+
+### User API Changes
+
+* Use the resolve's ICs for tools. (Cherry-pick of #18776) ([#18806](https://github.com/pantsbuild/pants/pull/18806))
+
+* Default to using the entire tool lockfile. (Cherry-pick of #18793) ([#18807](https://github.com/pantsbuild/pants/pull/18807))
+
+### Bug Fixes
+
+* Require urllib3<2, to reduce installation issues (cherry-pick of #18959) ([#18971](https://github.com/pantsbuild/pants/pull/18971))
+
+* Make `DigestSubset` symlink-aware (Cherry-pick of #18963) ([#18970](https://github.com/pantsbuild/pants/pull/18970))
+
+* Do not choke on missing lockfiles. (Cherry-pick of #18940) ([#18948](https://github.com/pantsbuild/pants/pull/18948))
+
+* Actually run deprecated targets fixer (Cherry-pick of #18860) ([#18893](https://github.com/pantsbuild/pants/pull/18893))
+
+* Remove existing entry if any when materialising symlink (Cherry-pick of #18873) ([#18878](https://github.com/pantsbuild/pants/pull/18878))
+
+* Ensure non-ambiguous args/env vars injection into PEXes (Cherry-pick of #18861) ([#18877](https://github.com/pantsbuild/pants/pull/18877))
+
+* Patch `StreamingWorkunitContext.get_expanded_specs()`. (Cherry-pick of #18713) ([#18866](https://github.com/pantsbuild/pants/pull/18866))
+
+* help backends: Only list enabled experimental backends unless advanced help. (Cherry-pick of #18821) ([#18867](https://github.com/pantsbuild/pants/pull/18867))
+
+* Include `pants.backend.url_handlers.s3` in pants distribution. (Cherry-pick of #18826) ([#18870](https://github.com/pantsbuild/pants/pull/18870))
+
+* Handle workdir="."/default properly in run_shell_command (Cherry-pick of #18840) ([#18850](https://github.com/pantsbuild/pants/pull/18850))
+
+* Write adhoc_tool(stdout/stderr="...") relative to workdir, support absolute paths (Cherry-pick of #18814) ([#18839](https://github.com/pantsbuild/pants/pull/18839))
+
+* Use build root as workdir for shell_command(workdir="") (Cherry-pick of #18813) ([#18832](https://github.com/pantsbuild/pants/pull/18832))
+
+### Performance
+
+* Optimize `Target` and `FieldSet` operations (cherry-pick #18917) ([#18944](https://github.com/pantsbuild/pants/pull/18944))
+
+### Documentation
+
+* update troubleshooting document about self-hosted action runner (Cherry-pick of #18900) ([#18943](https://github.com/pantsbuild/pants/pull/18943))
+
+* doc: mention `use_local_alias` for the `[docker].registries` option. (Cherry-pick of #18946) ([#18950](https://github.com/pantsbuild/pants/pull/18950))
+
+* Fix adhoc output_... example, document run_shell_command workdir changes (Cherry-pick of #18894) ([#18910](https://github.com/pantsbuild/pants/pull/18910))
+
+* Include `symbols` as topic in usage help. (Cherry-pick of #18825) ([#18869](https://github.com/pantsbuild/pants/pull/18869))
+
+* Update mypy and pytest documentation to refer to install_from_resolve (Cherry pick of #18791) ([#18858](https://github.com/pantsbuild/pants/pull/18858))
+
 ## 2.16.0rc1 (Apr 23, 2023)
 
 ### User API Changes