Update: Restrict GitHub Pages deployment to main branch only

Co-Authored-By: Amp <amp@ampcode.com>

Author: heikkitoivonen

.github/workflows/deploy.yml

@@ -2,9 +2,9 @@ name: Deploy to GitHub Pages
 
 on:
   push:
-    branches: [ main, master ]
+    branches: [ main ]
   pull_request:
-    branches: [ main, master ]
+    branches: [ main ]
 
 permissions:
   contents: read