build: do not build test sass files in legacy output

Looks like the exclude glob does not work as expected. Hence
the new theming bundle test fails as there is no theming
bundle when the legacy gulp tasks process Sass files.

Author: devversion

tools/package-tools/gulp/build-scss-pipeline.ts

@@ -15,6 +15,6 @@ gulpSass.compiler = nodeSass;
 
 /** Create a gulp task that builds SCSS files. */
 export function buildScssPipeline(sourceDir: string) {
-  return src(join(sourceDir, '**/!(test-).scss'))
+  return src(join(sourceDir, '**/!(test-*).scss'))
     .pipe(gulpSass({includePaths: sassIncludePaths}).on('error', gulpSass.logError));
 }