ci: bump test cache-version to rebuild stale MP3 MAD NIF

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: FelonEkonom

.github/workflows/ci.yml

@@ -14,3 +14,5 @@ jobs:
 
   test:
     uses: membraneframework/membrane_actions/.github/workflows/test.yml@main
+    with:
+      cache-version: 2