Don't show old freights in freights line

[alexmt]

Checklist

• [x I've searched the issue queue to verify this is not a duplicate bug report.
• [x] I've included steps to reproduce the bug.
• [x] I've pasted the output of kargo version.
• [ ] I've pasted logs, if applicable.

Description

It seems like the freight line keeps showing all the freights it's ever discovered . The UI is getting slower and slower with each new freight. Some way to cleanup old freights that belong to no stage is required.

Steps to Reproduce

Keep using Kargo and see how freights never disappear from freight line.

Version

v0.7.0

[jessesuen]

Discussed offline and it's an issue specific to our setup. The CronJob handles this. Closing.

[krancour]

@jessesuen @alexmt lmk if you think changes to the default gc settings are in order.