readline, repl, url, util: remove needless RegExp capturing

[vsemozhetbyt]

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

readline, repl, url, util

Use non-capturing grouping or remove capturing completely when:

• capturing is useless per se, e.g. in test() check;
• captured groups are not used afterward at all;
• some of the later captured groups are not used afterward.

[vsemozhetbyt]

CI: https://ci.nodejs.org/job/node-test-pull-request/8696/ (UPD: green).

[mscdex]

Can't this be combined with #13718 ?

[refack]

I'm +1 for explicitness. Do you know if this has any performance impact?

[refack]

Can't this be combined with #13718 ?

I'm +1 on thinking about this (both have an impact on the benchmark footprint 🤔)

[vsemozhetbyt]

@refack I did not measure, but this seem to be commonplace, e.g.:

Capturing groups have a performance penalty. If you don't need the matched substring to be recalled, prefer non-capturing parentheses (see below).
MDN

@mscdex Do you mean I should close this PR and add it as a commit to the #13718?

[mscdex]

@vsemozhetbyt Either way should work I think.

[vsemozhetbyt]

Added to #13718.