Update build.yaml

Author: NickM-27

.github/workflows/build.yaml

@@ -45,6 +45,7 @@ jobs:
         uses: subosito/flutter-action@v2
         with:
             channel: 'stable'
+            flutter-version: '2.5.1'
       - name: Build
         run: make
       - name: Run tests
@@ -61,7 +62,6 @@ jobs:
       - name: Flutter env
         uses: subosito/flutter-action@v2
         with:
-            flutter-version: '2.5.1'
             channel: 'stable'
 
   web-tests:
@@ -73,7 +73,6 @@ jobs:
       - name: Flutter env
         uses: subosito/flutter-action@v2
         with:
-            flutter-version: '2.5.1'
             channel: 'stable'
       - name: Run test
         working-directory: ./web