Dashboard - Don't handle having 3 the same visualisation columns in the widget after saving

[Angelodaniel]

Environment

SaaS (https://sentry.io/)

Steps to Reproduce

1. Create widget
2. Create 3 the same columns in the vizualisation section
3. Hit save

See Sentry issue: https://sentry.sentry.io/issues/7050468989/events/67207eae10054f9ca068593a4bcbcd6f/

Expected Result

Saved widget shows correctly

Actual Result

Internal error. Please try again.
https://demo.sentry.io/dashboard/127293/?project=5808623&statsPeriod=7d

Product Area

Dashboards

Link

No response

DSN

No response

Version

No response

[linear]

ENG-5973

[getsantry]

Auto-routing to @getsentry/product-owners-dashboards for triage ⏲️