docs(cron): Add note about luxon timezones (#11451)

Author: chargome

includes/javascript-crons-upsert.mdx

@@ -149,6 +149,13 @@ The amount of time (in minutes) your job is allowed to run before it's considere
 
 The `tz` where your job is running. This is usually your server's timezone, (such as `America/Los_Angeles`). See [list of tz database time zones](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones). Optional.
 
+<Note>
+
+`node-cron` allows you to pass luxon timezones, but you have to convert them to an IANA timezone when using Sentry (for example, using `DateTime.local().zoneName`).
+
+</Note>
+
+
 `failureIssueThreshold`:
 
 _requires SDK version `8.7.0` or higher_