Run CI on PR instead of main

.github/workflows/ci.yml

@@ -26,27 +26,16 @@ jobs:
     steps:
       - name: Checkout sources
         uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - name: Decrypt keyfile
         run: ./.github/scripts/decrypt_secret.sh
         env:
           KEYFILE_PASSPHRASE: ${{secrets.KEYFILE_PASSPHRASE}}
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(corepack yarn config get cacheFolder)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
       - name: Install Node.js
         uses: actions/setup-node@v3
         with:
           node-version: ${{matrix.node-version}}
-
       - name: Install dependencies
         run: corepack yarn install
       - name: Build