Update CI.yml to point to main branch instead of master

Author: Larbino1

.github/workflows/CI.yml

@@ -2,11 +2,11 @@ name: CI
 on:
   push:
     branches:
-      - master
+      - main
     tags: ['*']
   pull_request:
     branches:
-      - master
+      - main
 concurrency:
   # Skip intermediate builds: always.
   # Cancel intermediate builds: only if it is a pull request build.