Bump actions versions (#39)

Also been getting this NodeJS 20 deprecation
warning so try updating it all to their latest.

Author: nullsystem

.github/workflows/generate.yml

@@ -34,13 +34,13 @@ jobs:
       - name: Install deps
         run: sudo apt install lowdown imagemagick
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
       - name: Generate
         run: make
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v3
+        uses: actions/upload-pages-artifact@v5
         with:
           path: '_out'
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v4
+        uses: actions/deploy-pages@v5