[TraceQL] Invalid regex reported as 500 #3990
Description
Describe the bug
When Tempo responds with Response: \"invalid regex: it also returns 500:
ts=2024-08-21T20:54:38.236380589Z caller=log.go:168 level=warn trace_id=e5b664a2649a08ff4f7261f33d0bde8e msg="GET /tempo/api/v2/search/tag/span.foo/values?q=%7B%20span.foo%20%3D~%20%22%5B%22%7D (500)