checksrc.yml fix branch name

Author: vszakats

.github/workflows/checksrc.yml

@@ -7,10 +7,10 @@ name: 'Source'
 'on':
   push:
     branches:
-      - master
+      - main
   pull_request:
     branches:
-      - master
+      - main
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}