ci: switch pub publish to official dart reusable workflow

Author: Dev-Beom

.github/workflows/publish.yml

@@ -1,51 +1,16 @@
 name: Publish to pub.dev
 
 on:
-  release:
-    types:
-      - published
+  push:
+    tags:
+      - 'v[0-9]+.[0-9]+.[0-9]+*'
   workflow_dispatch:
 
 permissions:
   contents: read
-  id-token: write
 
 jobs:
   publish:
-    runs-on: ubuntu-latest
-    timeout-minutes: 20
-    if: github.event_name == 'workflow_dispatch' || startsWith(github.event.release.tag_name, 'v')
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Setup Flutter
-        uses: subosito/flutter-action@v2
-        with:
-          channel: stable
-          cache: true
-
-      - name: Verify release tag matches pubspec version
-        if: github.event_name == 'release'
-        run: |
-          version=$(grep '^version:' pubspec.yaml | awk '{print $2}')
-          if [ "v$version" != "${{ github.event.release.tag_name }}" ]; then
-            echo "Tag mismatch: pubspec version is v$version but release tag is ${{ github.event.release.tag_name }}"
-            exit 1
-          fi
-
-      - name: Install dependencies
-        run: flutter pub get
-
-      - name: Verify OIDC is available
-        run: |
-          if [ -z "${ACTIONS_ID_TOKEN_REQUEST_URL:-}" ]; then
-            echo "OIDC token endpoint is not available. Check workflow permissions."
-            exit 1
-          fi
-
-      - name: Validate package
-        run: flutter pub publish --dry-run
-
-      - name: Publish package
-        run: timeout 10m flutter pub publish -f
+    permissions:
+      id-token: write
+    uses: dart-lang/setup-dart/.github/workflows/publish.yml@v1