Enable Linux as well

Author: domesticmouse

flutter_ci_script_shared.sh

@@ -47,16 +47,10 @@ function ci_codelabs () {
             if [ -d "test" ]
             then
                 if grep -q "flutter:" "pubspec.yaml"; then
-
-                    # intro_flutter_gpu only runs with Impeller
                     if [ $CODELAB = 'intro_flutter_gpu' ]; then
-                        if [ $RUNNER_OS = 'macOS' ] || [ $RUNNER_OS = 'Windows' ]; then
-                            flutter config --enable-native-assets
-                            flutter build `echo $RUNNER_OS | tr '[:upper:]' '[:lower:]'` --debug
-                            flutter test --enable-impeller
-                        else
-                            echo "Skipping $CODELAB on $RUNNER_OS"
-                        fi
+                        flutter config --enable-native-assets
+                        flutter build `echo $RUNNER_OS | tr '[:upper:]' '[:lower:]'` --debug
+                        flutter test --enable-impeller
                     else
                         flutter test
                     fi