Update to karma to work with --nolegacy_external_runfiles

Closes #312

PiperOrigin-RevId: 218547300
diff --git a/internal/karma/karma.conf.js b/internal/karma/karma.conf.js
index 993f54f..fc80882 100644
--- a/internal/karma/karma.conf.js
+++ b/internal/karma/karma.conf.js
@@ -24,9 +24,9 @@
   // and return the path to extract executable
   function extractWebArchive(extractExe, archiveFile, executablePath) {
     try {
-      // Paths are relative to the 'external' folder within runfiles
-      extractExe = extractExe ? path.join('external', extractExe) : extractExe;
-      archiveFile = path.join('external', archiveFile);
+      // Paths are relative to the root runfiles folder
+      extractExe = extractExe ? path.join('..', extractExe) : extractExe;
+      archiveFile = path.join('..', archiveFile);
       const extractedExecutablePath = path.join(process.cwd(), executablePath);
       if (!extractExe) {
         throw new Error('No EXTRACT_EXE found');