Release 6.2.1 (2023-06-02)

Baseline:  758b44da

Release Notes:

+ Automatic code cleanup. (#18504)
+ Update relnotes scripts (#18503)
+ Fix https://github.com/bazelbuild/bazel/issues/18493. (#18512)
+ Fix formatting of release notes (#18533)
+ Use extension rather than local names in ModuleExtensionMetadata (#18535)

Acknowledgements:

This release contains contributions from many people at Google, as well as Fabian Meumertzheim, Pavan Singh.