Update action triggers to support required checks (#2)

Author: frasdav

.github/workflows/ci.yml

@@ -2,8 +2,9 @@
 name: CI
 
 on:
-  push:
+  merge_group:
   pull_request:
+  push:
   workflow_dispatch:
 
 jobs:
@@ -31,7 +32,7 @@ jobs:
         uses: actions/cache@v3
         with:
           path: ~/.local/share/virtualenvs
-          key: ${{ runner.os }}-pipenv-${{ hashFiles('**/Pipfile.lock') }}-ci
+          key: ${{ runner.os }}-pipenv-${{ hashFiles('**/Pipfile.lock') }}-dev
       - name: Install
         if: steps.cache-pipenv.outputs.cache-hit != 'true'
         run: make install_ci