Move between two repositories more cleanly during patch (#2172)

* fix: checkout multiple repos cleanly

* fix: ensure git apply exits cleanly

Author: JoshMock

.github/workflows/serverless-patch.yml

@@ -30,17 +30,21 @@ jobs:
         with:
           repository: elastic/elasticsearch-js
           ref: '${{ github.event.pull_request.merge_commit_sha }}'
-      - name: Generate patch file
-        run: |
-          git format-patch -1 --stdout ${{ github.event.pull_request.merge_commit_sha }} > /tmp/patch.diff
+          path: elasticsearch-js
       - uses: actions/checkout@v4
         with:
           repository: elastic/elasticsearch-serverless-js
           ref: main
-      - name: Apply patch to serverless
+          path: elasticsearch-serverless-js
+      - name: Generate patch file
+        run: |
+          cd $GITHUB_WORKSPACE/elasticsearch-js
+          git format-patch -1 --stdout ${{ github.event.pull_request.merge_commit_sha }} > /tmp/patch.diff
+      - name: Apply patch file
         run: |
+          cd $GITHUB_WORKSPACE/elasticsearch-serverless-js
           git checkout -b apply-patch-${{ github.event.pull_request.id }}
-          git apply -C1 --recount --reject /tmp/patch.diff
+          git apply -C1 --recount --reject /tmp/patch.diff || exit 0
           comment='Patch applied from elastic/elasticsearch-js#${{ github.event.pull_request.id }}'
           for f in $(find . -name '*.rej'); do
             comment="$comment\n\n## Rejected patch \`$f`\:\n\`\`\`\n$(cat $f)\n\`\`\`"