CI: run workflow on all branches, not just main

Allow contributors working on forks to get CI feedback on feature branches.

Author: fdcastel

.github/workflows/main.yml

@@ -2,8 +2,6 @@ name: CI and Deploy Docs
 
 on:
   push:
-    branches:
-      - main
   workflow_dispatch:
 
 permissions:
@@ -13,7 +11,7 @@ permissions:
   packages: write
 
 concurrency:
-  group: main
+  group: ${{ github.ref }}
 
 jobs:
   clang-format-check: