only build and push docker on merges to main

.github/workflows/ci.yml

@@ -4,8 +4,6 @@ on:
   push:
     branches:
       - main
-      - develop
-      - docker-publish
 jobs:
   build_and_test:
     runs-on: ${{ matrix.os }}
@@ -37,6 +35,7 @@ jobs:
     name: Build & Publish to Docker Hub
     needs: build_and_test
     runs-on: ubuntu-latest
+    if: ${{ github.event_name == 'push' }}
     steps:
       - name: Checkout
         uses: actions/checkout@v2