Track call rejoins

Call rejoins will be one of the KPIs we track in PostHog to measure call quality. I've also reverted the previous behavior which logged all OpenTelemetry spans to PostHog, since we should only be sending small, anonymized bits of data there.

src/analytics/PosthogAnalytics.ts

@@ -385,22 +385,6 @@ export class PosthogAnalytics {
     this.capture(eventName, properties, options);
   }
 
-  public async trackFromSpan(
-    { eventName, ...properties },
-    options?: CaptureOptions
-  ): Promise<void> {
-    if (this.identificationPromise) {
-      // only make calls to posthog after the identificaion is done
-      await this.identificationPromise;
-    }
-    if (
-      this.anonymity == Anonymity.Disabled ||
-      this.anonymity == Anonymity.Anonymous
-    )
-      return;
-    this.capture(eventName, properties, options);
-  }
-
   public startListeningToSettingsChanges(): void {
     // Listen to account data changes from sync so we can observe changes to relevant flags and update.
     // This is called -