Add base_branch as inputs

actions/commit_pr_and_merge/action.yaml

@@ -12,6 +12,10 @@ inputs:
   add:
     description: Comma- or newline-separated list of paths to add
     required: true
+  base_branch:
+    description: The base branch we want to merge into
+    type: string
+    default: ${{ github.ref_name }}
 outputs:
   git_tag_or_hash: 
     description: The git tag (or hash if no tag provided) of the merge commit
@@ -44,7 +48,7 @@ runs:
             repo: context.repo.repo,
             title: '[CI Pipeline] ${{ inputs.message }}',
             head: 'ci-${{ github.sha }}',
-            base: '${{ github.ref_name }}',
+            base: '${{ inputs.base_branch }}',
             body: '[CI Pipeline] Automated update'
           })).data;
           core.setOutput('pull-request-url', newPr.html_url);