Bump flutter version to 3.7

Author: rolandgeider

.github/workflows/android-release.yml

@@ -25,7 +25,7 @@ jobs:
         uses: subosito/flutter-action@v1
         with:
           channel: 'stable'
-          flutter-version: '3.3.x'
+          flutter-version: '3.7.x'
 
       - name: Decrypt config files
         run: |

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
       uses: subosito/flutter-action@v1
       with:
         channel: 'stable'
-        flutter-version: '3.3.x'
+        flutter-version: '3.7.x'
 
     - run: dart --version
     - run: flutter --version

.github/workflows/linter.yml

@@ -20,7 +20,7 @@ jobs:
         uses: subosito/flutter-action@v1
         with:
           channel: 'stable'
-          flutter-version: '3.3.x'
+          flutter-version: '3.7.x'
 
       - name: Get dependencies
         run: flutter pub get