Update workflow to latest Nikola build

Author: SimonR99

.github/workflows/main.yml

@@ -6,10 +6,8 @@ jobs:
     name: 'Deploy Nikola to GitHub Pages'
     steps:
     - name: Check out
-      uses: actions/checkout@v4
-      with:
-        fetch-depth: 0
+      uses: actions/checkout@v2
     - name: Build and Deploy Nikola
-      uses: getnikola/nikola-action@v2
-      env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      uses: getnikola/nikola-action@v4
+      with:
+        dry_run: false