Merge bitcoin#22507: doc: Adjust commit message template for the guix.sigs repo

fafade9 doc: Adjust commit message template for the guix.sigs repo (MarcoFalke)

Pull request description:

  Seems to be the most common template used, so adjust this here, too.

ACKs for top commit:
  laanwj:
    ACK fafade9
  hebasto:
    re-ACK fafade9

Tree-SHA512: 20477d14ecfad94f3b28b94786a4c0d98df539360d0c1deefa94766064a7d0700c849e54d6b251f922e135fcfa964ada0c724090f7f92b459ea39f7c3ca8c65d

Author: laanwj

doc/release-process.md

@@ -178,7 +178,7 @@ Commit your signature for the signed macOS/Windows binaries:
 ```sh
 pushd ./guix.sigs
 git add "${VERSION}/${SIGNER}"/all.SHA256SUMS{,.asc}
-git commit -m "Add ${SIGNER} ${VERSION} signed binaries signatures"
+git commit -m "Add attestations by ${SIGNER} for ${VERSION} codesigned"
 git push  # Assuming you can push to the guix.sigs tree
 popd
 ```