chore(deps): update withastro/action action to v4

Author: renovate[bot]

.github/workflows/deploy.yml

@@ -23,7 +23,7 @@ jobs:
       - name: enable corepack
         run: corepack enable
       - name: Install, build, and upload your site
-        uses: withastro/action@v3
+        uses: withastro/action@v4
         # with:
           # path: . # The root location of your Astro project inside the repository. (optional)
           # node-version: 20 # The specific version of Node that should be used to build your site. Defaults to 20. (optional)