add a github action to sync upstream branch to staging

.github/workflows/sync-repo-with-upstream.yml

@@ -0,0 +1,40 @@
+name: Sync Upstream to Staging
+
+on:
+  schedule:
+    - cron: '35 12 * * *' # Testing during daytime for now 
+  workflow_dispatch: # Allows manual triggering
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout the repository
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+
+    - name: Set up Git
+      run: |
+        git config --global user.name 'github-actions[bot]'
+        git config --global user.email 'github-actions[bot]@users.noreply.github.com'
+
+    - name: Add upstream remote
+      run: git remote add upstream https://github.com/jhaals/yopass.git
+
+    - name: Fetch upstream changes
+      run: git fetch upstream
+
+    - name: Checkout staging branch
+      run: git checkout staging
+
+    - name: Merge upstream changes excluding Dockerfile
+      run: |
+        git merge upstream/master --no-commit --no-ff
+        git reset HEAD Dockerfile
+        git checkout -- Dockerfile
+        git commit -m "Merge upstream changes excluding Dockerfile" # we have custom changes in Dockerfile we need to retain
+
+    - name: Push changes to the staging branch
+      run: git push origin staging