Prepare 2.5.1rc4. (pantsbuild#12260)

src/python/pants/notes/2.5.x.md

@@ -2,11 +2,19 @@
 
 See https://www.pantsbuild.org/v2.5/docs/release-notes-2-5 for an overview of the changes in this release series.
 
+## 2.5.1rc4 (Jun 30, 2021)
+
+### Bug fixes
+
+* Fix dependency inference to be ambiguous when >1 type stub for same module (Cherry-pick of #12244) ([#12245](https://github.com/pantsbuild/pants/pull/12245))
+
+* Fix `skip_tool` not working with `./pants fmt` if all files are skipped (Cherry-pick of #12230) ([#12233](https://github.com/pantsbuild/pants/pull/12233))
+
 ## 2.5.1rc3 (Jun 16, 2021)
 
 ### Bug fixes
 
-* Fix Process output capture re: working_directory. (#12197) ([#12198](https://github.com/pantsbuild/pants/pull/12198))
+* Fix Process output capture re: `working_directory`. (#12197) ([#12198](https://github.com/pantsbuild/pants/pull/12198))
 
 ## 2.5.1rc2 (Jun 02, 2021)