attempt merging

.github/workflows/create-merge-release-into-dev-pr.yml

@@ -25,13 +25,42 @@ jobs:
 
         echo "branch=${BRANCH}" >> $GITHUB_OUTPUT
 
-  create-pr:
+  try-merging:
     permissions:
-      pull-requests: write # for git push
+      contents: write # for git push
 
     runs-on: ubuntu-latest
     needs: setup
     timeout-minutes: 5
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          ref: test-dev # TODO: DELETE ME
+      - name: Try merging
+        run: |
+          git fetch --shallow-exclude "$BASE_BRANCH" origin "$RELEASE_BRANCH"
+          git fetch --shallow-exclude "$RELEASE_BRANCH" origin "$BASE_BRANCH"
+          git repack -d # https://stackoverflow.com/a/63879454/96823
+          git fetch --deepen 1 origin "$BASE_BRANCH" "$RELEASE_BRANCH"
+
+          git branch "$RELEASE_BRANCH" origin/"$RELEASE_BRANCH"
+
+          git diff ..."$RELEASE_BRANCH"
+          git merge --no-edit --no-ff "$RELEASE_BRANCH"
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          BASE_BRANCH: test-dev
+          RELEASE_BRANCH: ${{ needs.setup.outputs.latest_release_branch }}
+
+  create-pr:
+    permissions:
+      pull-requests: write # for creating pull request
+
+    runs-on: ubuntu-latest
+    needs: [setup, try-merging]
+    timeout-minutes: 5
+    if: false # TODO: DELETE ME
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4