fix workflow

Author: pfefferle

.github/workflows/update-assets.yml

@@ -10,7 +10,7 @@ jobs:
     steps:
     - uses: actions/checkout@v3
     - name: WordPress.org plugin asset/readme update
-      uses: 10up/action-wordpress-plugin-asset-update@master
+      uses: 10up/action-wordpress-plugin-asset-update@stable
       env:
         SVN_PASSWORD: ${{ secrets.SVN_PASSWORD }}
         SVN_USERNAME: ${{ secrets.SVN_USERNAME }}