git-repo-2.21-bp156.2.1

- remove obsolete patch fix-python-readlink.patch
- Update to version 2.21:
  * project: mark gc.log as safe to discard when migrating .git/
  * init: add an option --enable-git-lfs-filter
  * init: make bad --repo-rev settings more clear
  * project: Ignore failure to remove the sample hooks
  * branches: Fix "not in" handling
  * project: store objects in project-objects directly
  * project: move --reference handling to project-objects
  * test_project: use os.readlink instead of Path.readlink

- add fix-python-readlink.patch, fixing the project for python < 3.9.

- Update to version 2.20:
  * project: prune sample hooks
  * project: drop support for symlinking internal .git files
  * project: abort a bit earlier before migrating .git/
  * Revert "sync: dropped "NOTICE: --use-superproject is in beta ..." message."
  * project: stop symlinking info dir under .git/
  * project: stop symlinking description file under .git/
  * project: stop symlinking svn under .git/
  * project: clean up now unused code
  * sync: dropped "NOTICE: --use-superproject is in beta ..." message.
  * sync: With --mirror option, don't display no-use-superproject... message.

- Update to version 2.19:
  * project: migrate worktree .git/ dirs to symlinks
  * init, sync: fixed flake8 warnings.
  * superproject: Inherit --no-use-superproject with --mirror option.
  * sync: Handle tag ref in "upstream" field
  * project: init hooks in objdir only
  * sync: link the internal-fs-layout doc into checkouts
  * git-review: add config file
  * SUBMITTING_PATCHES: link to commit message style docs
  * man: refresh pages
  * help: fix grammar in help text

- initial package for version 2.19.