ci: Trigger on 'main' branch

'master' branch has been renamed to 'main'.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>

Author: stephanosio

.github/workflows/ci.yml

@@ -2,10 +2,10 @@ name: CI
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
     tags: [ 'v*' ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 permissions:
   packages: write