GitHub: use master branch for litd itests again

Author: guggero

.github/workflows/main.yaml

@@ -21,7 +21,7 @@ env:
 
   GO_VERSION: '1.23.6'
 
-  LITD_ITEST_BRANCH: 'script-key-migrations'
+  LITD_ITEST_BRANCH: 'master'
 
 jobs:
   #######################