Align prepare-release-branch comment to 'for git push to PR branch'

Standardize permissions comment for consistency across repositories.

Author: trask

.github/workflows/prepare-release-branch.yml

@@ -25,7 +25,7 @@ jobs:
 
   create-pull-request-against-release-branch:
     permissions:
-      contents: write  # for Git to git push
+      contents: write  # for git push to PR branch
     runs-on: ubuntu-latest
     needs:
       - prereqs
@@ -82,7 +82,7 @@ jobs:
 
   create-pull-request-against-main:
     permissions:
-      contents: write  # for Git to git push
+      contents: write  # for git push to PR branch
     runs-on: ubuntu-latest
     needs:
       - prereqs