[wip] testing subnet-evm sync workflow

.github/workflows/sync-subnet-evm-branch.yml

@@ -5,7 +5,7 @@ on:
         remoteBranch:
             description: "Subnet EVM Branch"
             required: true
-            default: "master"
+            default: "coreth-test-0"
 
 jobs:
   sync_branch:
@@ -17,4 +17,49 @@ jobs:
       - uses: actions/setup-go@v5
         with:
           go-version: "~1.21.12"
-          check-latest: true
+          check-latest: true
+
+      - name: Add Remote
+        run: |
+          git remote add subnet-evm https://github.com/ava-labs/subnet-evm
+
+      # TODO: Replace test branch with actual (eg, coreth)
+      - name: Fetch Remote Branch (${{ github.event.inputs.remoteBranch }})
+        id: fetch_remote_branch
+        run: |
+          git fetch subnet-evm ${{ github.event.inputs.remoteBranch }}
+          git fetch subnet-evm coreth-diff-script
+          result=$(git rev-parse --short=8 subnet-evm/${{ github.event.inputs.remoteBranch }})
+          echo result="${result}" >> "${GITHUB_OUTPUT}"
+
+      # TODO: Remove this step when the script is checked in
+      - name: Checkout script
+        run: |
+          git checkout subnet-evm/coreth-diff-script -- ./scripts/apply_diff_and_rename.sh
+
+      - name: Apply diff
+        run: |
+          ./scripts/apply_diff_and_rename.sh subnet-evm/${{ github.event.inputs.remoteBranch }}
+
+      # TODO: Should this step be removed?
+      - name: Restore .github/workflows
+        run: |
+          git checkout -- .github/workflows
+
+      # TODO: Using a single branch to iterate for now (avoid maing noise in notifications)
+      - name: Create Pull Request
+        id: create_pr
+        uses: peter-evans/create-pull-request@v6
+        with:
+          commit-message: "Sync subnet-evm to ${{ steps.fetch_remote_branch.outputs.result }}"
+          branch: auto-sync-subnet-evm
+          title: "Sync Subnet EVM to ${{ steps.fetch_remote_branch.outputs.result }}"
+          body: |
+            This PR was created automatically by a GitHub Action.
+          draft: true
+
+      - name: PR Outputs
+        if: ${{ steps.create_pr.outputs.pull-request-number }}
+        run: |
+          echo "Pull Request Number - ${{ steps.create_pr.outputs.pull-request-number }}"
+          echo "Pull Request URL - ${{ steps.create_pr.outputs.pull-request-url }}"