chore: Trace RRule

There is a 5s gap in the traces from fetching all the meeting series'
last meetings and starting the new ones. In this time we only do some
RRule parsing and calculations. Let's trace these.

packages/server/graphql/private/mutations/processRecurrence.ts

@@ -187,7 +187,9 @@ const processRecurrence: MutationResolvers['processRecurrence'] = async (_source
 
         // For meetings that should still be active, start the meeting and set its end time.
         // Any subscriptions are handled by the shared meeting start code
-        const rrule = RRule.fromString(meetingSeries.recurrenceRule)
+        const rrule = tracer.trace('RRule.fromString', () =>
+          RRule.fromString(meetingSeries.recurrenceRule)
+        )
         // technically, RRULE should never return NaN here but there's a bug in the library
         // https://github.com/jakubroztocil/rrule/issues/321
         if (isNaN(rrule.options.interval)) {
@@ -202,9 +204,8 @@ const processRecurrence: MutationResolvers['processRecurrence'] = async (_source
               Math.max(lastMeeting.createdAt.getTime() + ms('10m'), now.getTime() - ms('24h'))
             )
           : new Date(0)
-        const newMeetingsStartTimes = rrule.between(
-          getRRuleDateFromJSDate(fromDate),
-          getRRuleDateFromJSDate(now)
+        const newMeetingsStartTimes = tracer.trace('RRule.between', () =>
+          rrule.between(getRRuleDateFromJSDate(fromDate), getRRuleDateFromJSDate(now))
         )
         for (const startTime of newMeetingsStartTimes) {
           const err = await tracer.trace('startRecurringMeeting', async (span) => {