ci(ci.yml): force to use main instead of master

Author: AlcidesRC

.github/workflows/ci.yml

@@ -2,9 +2,9 @@ name: Continuous Integration
 
 on:
     push:
-        branches: [ "master" ]
+        branches: [ "main" ]
     pull_request:
-        branches: [ "master" ]
+        branches: [ "main" ]
 
 permissions:
     contents: read