Make sure generated files don't change during build.

.github/workflows/linux.yml

@@ -42,6 +42,9 @@ jobs:
     - name: Build the app
       run: flutter build linux
 
+    - name: Check generated files
+      run: git diff --exit-code
+
     - name: Rename and archive app
       run: |
         export REF=$(echo ${GITHUB_REF} | cut -d '/' -f 3)

.github/workflows/macos.yml

@@ -39,6 +39,9 @@ jobs:
     - name: Build the app
       run: flutter build macos
 
+    - name: Check generated files
+      run: git diff --exit-code
+
     - name: Rename and archive app bundle
       run: |
         export REF=$(echo ${GITHUB_REF} | cut -d '/' -f 3)

.github/workflows/windows.yml

@@ -38,6 +38,9 @@ jobs:
       - name: Build the app
         run: flutter build windows
 
+      - name: Check generated files
+        run: git diff --exit-code
+
       - name: Move .dll files
         run: |
           $dest = "build\windows\runner\Release"