update workflow

Author: kaishuu0123

.github/workflows/electron-build.yml

@@ -28,7 +28,7 @@ jobs:
         run: |
           yarn build:win
       - name: Import Apple installer signing certificate
-        if: matrix.os.matrix == 'macos'
+        if: ${{ matrix.os == 'macos-latest'}}
         uses: Apple-Actions/import-codesign-certs@v2
         with:
           p12-file-base64: ${{ secrets.APPLE_DEV_ID_APP }}