ci: add workflow for updating package API snapshots

.github/workflows/package_api.yml

@@ -0,0 +1,48 @@
+name: Package API
+on:
+  pull_request_target:
+    types:
+      - labeled
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: write
+
+jobs:
+  update:
+    if: >
+      github.event.pull_request.head.repo.full_name == 'primer/octicons' &&
+      contains(github.event.pull_request.labels.*.name, 'api changes approved') }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout default branch
+        uses: actions/checkout@v3
+        with:
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
+          ref: ${{ github.head_ref }}
+      - uses: actions/setup-node@v3
+        with:
+          node-version: '16.x'
+          registry-url: 'https://registry.npmjs.org'
+      - name: Install dependencies
+        run: yarn
+      - name: Install workspace dependencies
+        working-directory: lib/octicons_react
+        run: yarn
+      - name: Build project
+        run: yarn build
+      - name: Build package
+        working-directory: lib/octicons_react
+        run: yarn build
+      - name: Update snapshots
+        working-directory: lib/octicons_react
+        run: yarn test -u
+      - uses: stefanzweifel/git-auto-commit-action@v4
+        with:
+          commit_message: 'chore(project): update @primer/octicons-react Public API'
+      - uses: actions-ecosystem/action-remove-labels@v1
+        with:
+          labels: 'api changes approved'