Updates workflow file for docs build to use DEPLOY_TOKEN

Reference: https://github.com/laminas/documentation-theme/tree/master/github-actions/docs#environment
Signed-off-by: Frank Brückner <[email protected]>

.github/workflows/docs-build.yml

@@ -13,4 +13,4 @@ jobs:
       - name: Build Docs
         uses: laminas/documentation-theme/github-actions/docs@master
         env:
-          DOCS_DEPLOY_KEY: ${{ secrets.DOCS_DEPLOY_KEY }}
+          DEPLOY_TOKEN: ${{ secrets.GITHUB_TOKEN }}