readline: align delete-word-right span with word-right - #65180

Description

[kDeleteWordRight]() in lib/internal/readline/interface.js matched the
text after the cursor with /^(?:\s+|\W+|\w+)\s*/. Its three sibling
word-motion handlers all use [^\w\s]+ (a run of punctuation, excluding
whitespace) for the symbol-run alternative:

• [kWordLeft] — /^\s*(?:[^\w\s]+|\w+)?/
• [kWordRight] — /^(?:\s+|[^\w\s]+|\w+)\s*/
• [kDeleteWordLeft] — /^\s*(?:[^\w\s]+|\w+)?/

\W also matches whitespace, so delete-word-right (Meta+d,
Ctrl+Delete, Meta+Delete) removes a different span
than word-right (Meta+f, Ctrl+Right) traverses
whenever the text ahead of the cursor is punctuation, then whitespace,
then more punctuation.

Reproduction (built from this branch's parent, terminal: true):

line "-> => x", cursor at column 0
  word-right         -> advances over "-> "     (cursor at 3)
  delete-word-right  -> deletes "-> => ", leaving "x"   (should leave "=> x")

Forward-word and kill-word are expected to cover the same span (as they
do in bash / GNU readline / emacs), and the other three handlers already
agree with each other. This aligns [kDeleteWordRight] with
[kWordRight] by using [^\w\s]+.

Verification

• Reproduced on a from-source build of main; the new regression test
  fails on the unpatched source (actual: 'x', expected: '=> x') and
  passes with the fix.
• Regression tests added to test-readline-interface.js and
  test-readline-promises-interface.js (covering all three key bindings).
• Full test/parallel/test-readline*.js suite (21 files): all pass. The
  existing word-only cases are unaffected (both regexes agree on \w).