Update release tag in testing. (#7960)

* Update release tag in testing.

* Test workflow

Author: granluo

.github/workflows/release.yml

@@ -1,6 +1,9 @@
 name: release
 
 on:
+  pull_request:
+    paths:
+    - 'scripts/release_testing_setup.sh'
   workflow_dispatch:
   schedule:
     # Run every day at 11pm (PST) - cron uses UTC times

scripts/release_testing_setup.sh

@@ -45,8 +45,10 @@ git config --global user.email "google-oss-bot@example.com"
 git config --global user.name "google-oss-bot"
 git checkout "${podspec_repo_branch}"
 if [ "$TESTINGMODE" = "release_testing" ]; then
-  # Latest release branch on the repo, e.g. Cocoapods-7.9.0
-  latest_release_branch_tag=$(git branch -l -r --sort=-v:refname origin/release-* | head -n 1 | sed -n 's/origin\/release/CocoaPods/p')
+  # Latest release branch with prefix CocoaPods, e.g. CocoaPods-7.11
+  latest_branch_version=$(git branch -l -r --sort=-v:refname origin/release-* | head -n 1 | sed -n 's/^[ \t]*origin\/release/CocoaPods/p' )
+  # Latest tag of release branch on the repo, e.g. Cocoapods-7.9.0
+  latest_release_branch_tag=$(git tag -l --sort=-version:refname "$latest_branch_version"*[0-9] | head -n 1)
   echo "Podspecs tags of Nightly release testing will be updated to ${latest_release_branch_tag}."
   # Update source and tag, e.g.  ":tag => 'CocoaPods-' + s.version.to_s" to
   # ":tag => 'CocoaPods-7.9.0'"