feat(ga4): disalbe ga4 in localhost

Ref:
https://discourse.gohugo.io/t/how-to-exclude-google-analytics-when-running-under-hugo-local-server/6092/35

Author: timfanda35

themes/simplecss/layouts/partials/footer.html

@@ -18,4 +18,6 @@
   </div>
 </footer>
 
-{{ template "_internal/google_analytics.html" . }}
+{{- if not .Site.IsServer -}}
+  {{ template "_internal/google_analytics.html" . }}
+{{- end -}}