Update subosito/flutter-action action to v2.21.0 (#1474)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/backward_compatibility.yml

@@ -76,7 +76,7 @@ jobs:
           cat pubspec.yaml
 
       - name: Setup Flutter
-        uses: subosito/flutter-action@e938fdf56512cc96ef2f93601a5a40bde3801046 # v2.19.0
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e # v2.21.0
         with:
           flutter-version-file: packages/${{ matrix.package }}/pubspec.yaml
       - run: flutter test
@@ -112,7 +112,7 @@ jobs:
           # output for debugging
           cat pubspec.yaml
       - name: Setup Flutter
-        uses: subosito/flutter-action@e938fdf56512cc96ef2f93601a5a40bde3801046 # v2.19.0
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e # v2.21.0
         with:
           channel: ${{ matrix.channel }}
       - run: flutter test

.github/workflows/demo_app.yml

@@ -25,7 +25,7 @@ jobs:
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Setup Flutter
-        uses: subosito/flutter-action@e938fdf56512cc96ef2f93601a5a40bde3801046 # v2.19.0
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e # v2.21.0
         with:
           cache: true
       - uses: gradle/actions/setup-gradle@06832c7b30a0129d7fb559bcc6e43d26f6374244 # v4.3.1

.github/workflows/flutter.yml

@@ -28,7 +28,7 @@ jobs:
         if: github.base_ref
 
       - name: Setup Flutter
-        uses: subosito/flutter-action@e938fdf56512cc96ef2f93601a5a40bde3801046 # v2.19.0
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e # v2.21.0
         with:
           cache: true
 

.github/workflows/flutter_beta.yml

@@ -23,7 +23,7 @@ jobs:
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Setup Flutter
-        uses: subosito/flutter-action@e938fdf56512cc96ef2f93601a5a40bde3801046 # v2.19.0
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e # v2.21.0
         with:
           channel: beta
       - run: ./tool/test.sh

.github/workflows/flutter_master.yml

@@ -23,7 +23,7 @@ jobs:
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Setup Flutter
-        uses: subosito/flutter-action@e938fdf56512cc96ef2f93601a5a40bde3801046 # v2.19.0
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e # v2.21.0
         with:
           channel: master
       - run: ./tool/test.sh

.github/workflows/integration_test.yml

@@ -20,7 +20,7 @@ jobs:
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Setup Flutter
-        uses: subosito/flutter-action@e938fdf56512cc96ef2f93601a5a40bde3801046 # v2.19.0
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e # v2.21.0
         with:
           cache: true
       - uses: gradle/actions/setup-gradle@06832c7b30a0129d7fb559bcc6e43d26f6374244 # v4.3.1
@@ -67,7 +67,7 @@ jobs:
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Setup Flutter
-        uses: subosito/flutter-action@e938fdf56512cc96ef2f93601a5a40bde3801046 # v2.19.0
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e # v2.21.0
         with:
           cache: true