Revert "fix(ci): use Flutter action instead of Dart in reusable workflow"

This reverts commit d5f1e22.

Author: grdsdev

.github/workflows/dart-package-test.yml

@@ -51,11 +51,21 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
-      - name: Setup Flutter (includes Dart)
-        uses: subosito/flutter-action@v2
+      - name: Setup Dart
+        uses: dart-lang/setup-dart@v1
         with:
-          channel: ${{ matrix.sdk }}
-          cache: true
+          sdk: ${{ matrix.sdk }}
+
+      - name: Cache pub dependencies
+        uses: actions/cache@v4
+        with:
+          path: |
+            ${{ env.PUB_CACHE }}
+            ~/.pub-cache
+          key: ${{ runner.os }}-pub-${{ matrix.sdk }}-${{ hashFiles('**/pubspec.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-pub-${{ matrix.sdk }}-
+            ${{ runner.os }}-pub-
 
       - name: Bootstrap workspace
         run: |