githubci: update Litd itest branch

Author: GeorgeTsagk

.github/workflows/main.yaml

@@ -21,7 +21,7 @@ env:
 
   GO_VERSION: '1.24.6'
 
-  LITD_ITEST_BRANCH: 'tapd-main-branch'
+  LITD_ITEST_BRANCH: 'master'
 
 jobs:
   #######################