fix(setup-flutter): avoid deleting flutter.version.json when already cached to prevent concurrent pub failures

setup-flutter/action.yml

@@ -72,6 +72,7 @@ runs:
           }
           git -C "$SDK_DIR" config --global --add safe.directory "$SDK_DIR" || true
           git -C "$SDK_DIR" checkout "$TARGET_VERSION"
+          rm -f "$SDK_DIR/bin/cache/flutter.version.json"
         else
           git -C "$SDK_DIR" config --global --add safe.directory "$SDK_DIR" || true
           CURRENT_COMMIT=$(git -C "$SDK_DIR" rev-parse HEAD 2>/dev/null || true)
@@ -79,6 +80,7 @@ runs:
             echo "Checking out Flutter $TARGET_VERSION..."
             git -C "$SDK_DIR" fetch origin "$TARGET_VERSION" --depth=1 2>/dev/null || git -C "$SDK_DIR" fetch origin
             git -C "$SDK_DIR" checkout "$TARGET_VERSION"
+            rm -f "$SDK_DIR/bin/cache/flutter.version.json"
           else
             echo "Flutter SDK already at $TARGET_VERSION. Ready to use."
           fi
@@ -96,9 +98,15 @@ runs:
         echo "$SDK_DIR/bin" >> "$GITHUB_PATH"
 
         if [ "${{ inputs.enable_windowing }}" = "true" ]; then
-          "$SDK_DIR/bin/flutter" config --enable-windowing
+          if ! grep -q '"enable-windowing":[[:space:]]*true' "$HOME/.flutter_settings" 2>/dev/null; then
+            "$SDK_DIR/bin/flutter" config --enable-windowing
+          fi
+        fi
+        if [ ! -f "$SDK_DIR/bin/cache/flutter.version.json" ]; then
+          "$SDK_DIR/bin/flutter" --version
+        else
+          cat "$SDK_DIR/bin/cache/flutter.version.json"
         fi
-        "$SDK_DIR/bin/flutter" --version
 
         rm -rf "$LOCK_DIR" || true