Normative references to discontinued specs in Server Timing

[dontcallmedom-bot]

While crawling Server Timing, the following normative references were detected as pointing to discontinued specifications:

• [ ] RFC7230 has been obsoleted by rfc9110,rfc9112

_{This issue was detected and reported semi-automatically by Strudy based on data collected in webref.}

[clelland]

Should be a straight replacement with 9110, possibly directly linking to https://httpwg.org/specs/rfc9110.html#fields.components