[Gitar] Apply gitar duet on top of gitar bot PRs (#8141)

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## About the changes

When working with automated changes made by the @gitar-bot , custom
automated changes may be necessary. For example,

- Running lint auto-fixes
- Executing code generation
- Updating test snapshot files
- Running internal tools

Gitar recommends these in a separate CI pipeline. We call this [Gitar
Duet](https://gitar.co/docs/more/custom-automated-changes/), where
custom tools run alongside Gitar’s automated changes.

### Important files
github ci workflow files

## Discussion points
Feel free to update the workflow to modify the autofix steps

.github/workflows/gitar-duet-action.yml

@@ -0,0 +1,51 @@
+name: Gitar Duet
+
+on:
+  push:
+    branches:
+      - 'gitar_*'
+
+jobs:
+  gitar-duet:
+    if: github.event.head_commit.author.name == 'Gitar'
+    runs-on: ubuntu-latest
+    name: Gitar Duet
+    permissions:
+      contents: write # Required to update with Gitar Duet changes
+
+    steps:
+      - run: |
+          echo '${{ toJSON(github.event) }}'
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+          fetch-depth: 0
+
+      - name: Use Node.js 20
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20.x
+          cache: 'yarn'
+
+      - name: Enable corepack
+        run: corepack enable
+
+      - run: yarn install --immutable
+        env:
+          YARN_ENABLE_SCRIPTS: false
+
+      - run: |
+          yarn run biome check --fix --unsafe || true # Run unsafe auto-fixes
+          yarn lint:fix || true # Fix linting issues
+
+      - run: yarn test:updateSnapshot || true # Update test snapshots
+
+      - run: |
+          # Undo deletes for snapshots
+          git reset
+          git diff --diff-filter=D --name-only HEAD | xargs git checkout HEAD^ --
+
+      - name: Run Gitar Duet Action
+        uses: gitarcode/gitar-duet-action@v1
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}

package.json

@@ -58,6 +58,7 @@
     "test:watch": "yarn test --watch",
     "test:coverage": "NODE_ENV=test PORT=4243 jest --coverage --testLocationInResults --outputFile=\"coverage/report.json\" --forceExit --testTimeout=10000",
     "test:coverage:jest": "NODE_ENV=test PORT=4243 jest --silent --ci --json --coverage --testLocationInResults --outputFile=\"report.json\" --forceExit --testTimeout=10000",
+    "test:updateSnapshot": "NODE_ENV=test PORT=4243 jest --updateSnapshot --testTimeout=10000",
     "seed:setup": "ts-node --compilerOptions '{\"strictNullChecks\": false}' src/test/e2e/seed/segment.seed.ts",
     "seed:serve": "UNLEASH_DATABASE_NAME=unleash_test UNLEASH_DATABASE_SCHEMA=seed yarn run start:dev",
     "clean": "del-cli --force dist",
@@ -247,4 +248,4 @@
     ]
   },
   "packageManager": "yarn@4.4.1"
-}
+}