chore(deps): update dependency getzola/zola to v0.21.0

Author: renovate[bot]

netlify.toml

@@ -6,7 +6,7 @@ command = "pnpm build"
 
 [build.environment]
 # Set the version name that you want to use and Netlify will automatically use it.
-ZOLA_VERSION = "v0.19.2"
+ZOLA_VERSION = "v0.21.0"
 NODE_VERSION = "22"
 BUILD_MODE = "production"