[BUG] event_map shortcode hard-fails the Hugo build when coordinates is blank

[mattstratton]

themes/devopsdays-theme/layouts/shortcodes/event_map.html reads coordinates before it checks whether there is anything to render:

{{- $e := partial "functions/get-event-data" . -}}
{{- $coords := split $e.coordinates "," -}}
{{- $lat := index $coords 0 -}}
{{- $lng := index $coords 1 -}}

{{- with $e.location_address -}}
<iframe ...

Two problems:

1. $lat and $lng are never used. The iframe is built from location_address. The three lines that compute them are dead.
2. They break the build when coordinates is blank. split on a nil value errors, and it happens outside the with guard, so it runs even for events that have no address at all.

This is a live trap rather than a theoretical one: utilities/docs/cancel-event.md instructs organizers to blank coordinates when cancelling an event. If that event's location.md still contains {{< event_map >}}, the whole site build fails.

coordinates is marked DEPRECATED in reference.md and nothing else consumes it.

Suggested fix: delete the three $coords/$lat/$lng lines.

Found while documenting the repo for AI coding assistants.