Don't run release pipeline on PR/push

Author: hasufell

.github/workflows/release.yaml

@@ -2,14 +2,9 @@ name: Build and release
 
 on:
   push:
-    branches:
-      - master
     tags:
       - 'v*'
       - 'cabal-install-*'
-  pull_request:
-    branches:
-      - master
   schedule:
     - cron: '0 0 * * *'
   workflow_dispatch: