Make a QUIC optout tag to build without QUIC support

[Jorropo]

Checklist

• My issue is specific & actionable.
• I am not suggesting a protocol enhancement.
• I have searched on the issue tracker for my issue.

Description

As some of you know the QUIC lib we use do some unsafe magic to edit private fields of structs in the crypto golang std libs.
That because the golang crypto libs are not exposing TLS details that you need to change if you do custom stuff.

To do that the quic lib (and transport by extension) are gated to specific golang versions because if the struct internally changed, the offsets or logic need to be manually updated.

I'm using the go1.19 branch from time to time and get tired to patch out the same 4 lines of code over and over.
If I could do:

go build -tags=noQUIC .

My life would be easier.

[BigLep]

@Jorropo : thanks for raising. We're not apt to tackle this because of extra maintenance. We don't want to take on testing/maintaining it because others have started relying on it. Others on the team do build modifications and just have them stashed locally.

It would be good to get more user signal as to how important build flags like this are for the community. We'll leave it open for now to collect that.