Revert "JS: Fix check to account for override in tests"

This reverts commit 81bb07a.

Author: asgerf

javascript/extractor/src/com/semmle/js/extractor/AutoBuild.java

@@ -490,10 +490,7 @@ public int run() throws IOException {
       }
 
       // Fail extraction if no relevant files were found.
-      boolean seenRelevantFiles = EnvironmentVariables.isActionsExtractor()
-        ? seenFiles // assume all files are relevant for Actions extractor
-        : hasSeenCode();
-      if (!seenRelevantFiles) {
+      if (!seenFiles || !hasSeenCode() && !EnvironmentVariables.isActionsExtractor()) {
         if (seenFiles) {
           warn("Only found JavaScript or TypeScript files that were empty or contained syntax errors.");
         } else {