[release 2.13] Apply Release only changes to 2.13 branch

Release-only changes for the release/2.13 branch cut, produced by
running scripts/release/apply-release-changes.sh. The script repoints
reusable workflows and composite actions from @main to @release/2.13,
rewrites templates to release/2.13 (with checkout_pr_head=False so PRs
build the...