Website: update contact form button (#50477)

Changes:
- updated the submit button on the "Talk to us" form ("Talk to an
engineer" » "Pick a time")
- Updated the GitHub webhook to add ~ga4-annotation labels to pull
requests that change the contact page

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Updated the contact form button label to “Pick a time” for clearer
scheduling intent.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

website/api/controllers/webhooks/receive-from-github.js

@@ -380,7 +380,7 @@ module.exports = {
         }, baseHeaders).retry(), 'filename');// (don't worry, it's the whole path, not the filename)
 
         // Create an array of paths that will determine if the "~ga4-annotation" label will be automatically added to this PR.
-        let CHANGED_PATHS_THAT_CREATE_ANALYTICS_ANNOTATIONS = [ 'website/views/pages/homepage.ejs', 'website/views/pages/pricing.ejs', 'website/views/partials/primary-tagline.partial.ejs'];
+        let CHANGED_PATHS_THAT_CREATE_ANALYTICS_ANNOTATIONS = [ 'website/views/pages/homepage.ejs', 'website/views/pages/pricing.ejs', 'website/views/partials/primary-tagline.partial.ejs', 'website/views/pages/contact.ejs'];
         let prShouldCreateGoogleAnalyticsAnnotation = false;
 
         // For each changed file, decide what reviewer to request, if any…

website/views/pages/contact.ejs

@@ -119,7 +119,7 @@
          </cloud-error>
           <cloud-error v-if="cloudError && cloudError !== 'invalidEmailDomain'"></cloud-error>
           <div class="form-group btn-container">
-            <ajax-button type="submit" purpose="submit-button" syncing-message="Looking up availability…" :syncing="syncing" class="btn btn-primary">Talk to an engineer</ajax-button>
+            <ajax-button type="submit" purpose="submit-button" syncing-message="Looking up availability…" :syncing="syncing" class="btn btn-primary">Pick a time</ajax-button>
           </div>
         </ajax-form>
       </div>