fix: add master branch to GitHub Actions workflow triggers

- Add master branch to both push and pull_request triggers
- Resolves workflow execution issues for PRs targeting master branch

Author: GordonSmith

.github/workflows/release-please.yml

@@ -4,11 +4,13 @@ on:
   push:
     branches:
       - main
+      - master
       - candidate-*
 
   pull_request:
     branches:
       - main
+      - master
       - candidate-*
 
 permissions: