fix deploy of docu via gh actions

Author: MalteKurz

.github/workflows/deploy_docu.yml

@@ -77,7 +77,7 @@ jobs:
 
     - name: Deploy to dev
       if: ${{ github.event_name == 'workflow_dispatch' || github.event_name == 'push' }}
-      uses: JamesIves/github-pages-deploy-action@3.7.1
+      uses: JamesIves/github-pages-deploy-action@v4
       with:
         repository-name: DoubleML/doubleml.github.io
         branch: main
@@ -93,7 +93,7 @@ jobs:
 
     - name: Deploy to version
       if: ${{ github.event_name == 'release' }}
-      uses: JamesIves/github-pages-deploy-action@3.7.1
+      uses: JamesIves/github-pages-deploy-action@v4
       with:
         repository-name: DoubleML/doubleml.github.io
         branch: main
@@ -106,7 +106,7 @@ jobs:
 
     - name: Deploy to stable
       if: ${{ github.event_name == 'release' }}
-      uses: JamesIves/github-pages-deploy-action@3.7.1
+      uses: JamesIves/github-pages-deploy-action@v4
       with:
         repository-name: DoubleML/doubleml.github.io
         branch: main