fix flutter version for reproducible builds

Author: Dr-Blank

.github/workflows/flutter_release.yaml

@@ -30,6 +30,7 @@ jobs:
         uses: subosito/flutter-action@v2
         with:
           channel: "stable"
+          flutter-version-file: pubspec.yaml
 
       - name: Install dependencies
         run: flutter pub get

pubspec.yaml

@@ -20,7 +20,7 @@ version: 0.0.15+6
 
 environment:
   sdk: ">=3.3.4 <4.0.0"
-  flutter: ">=3.24.5 <4.0.0"
+  flutter: 3.24.5
 
 isar_version: &isar_version ^4.0.0-dev.13 # define the version to be used