Rust named capture groups appear as errors

[esemeniuc]

Bug Description

This example fails in regex101: https://docs.rs/regex/latest/regex/#example-named-capture-groups

Docs:
https://docs.rs/regex/latest/regex/#grouping-and-flags

Reproduction steps

I enter Homer (?<middle>.)\. Simpson using the rust option, and I see the following:

Expected Outcome

I expect to see a capture group for the middle name.

Browser

Firefox 122.0

OS

Arch Linux, kernel 6.6

[firasdib]

See #2167