Merge tag 'v5.15.15' into v5.15/standard/base

This is the 5.15.15 stable release

# gpg: Signature made Sun 16 Jan 2022 03:13:05 AM EST
# gpg:                using RSA key 647F28654894E3BD457199BE38DBBDC86092693E
# gpg: Can't check signature: No public key