Update Rust crate regex to v1.9.1

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
regex	dependencies	minor	1.8.4 -> 1.9.1
regex	dependencies	minor	1.8 -> 1.9

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Release Notes

rust-lang/regex (regex)

v1.9.1

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==================
This is a patch release which fixes a memory usage regression. In the regex
1.9 release, one of the internal engines used a more aggressive allocation
strategy than what was done previously. This patch release reverts to the
prior on-demand strategy.

Bug fixes:

• BUG #​1027:
  Change the allocation strategy for the backtracker to be less aggressive.

v1.9.0

Compare Source

==================
This release marks the end of a years long rewrite of the regex crate
internals. Since this is
such a big release, please report any issues or regressions you find. We would
also love to hear about improvements as well.

In addition to many internal improvements that should hopefully result in
"my regex searches are faster," there have also been a few API additions:

• A new Captures::extract method for quickly accessing the substrings
  that match each capture group in a regex.
• A new inline flag, R, which enables CRLF mode. This makes . match any
  Unicode scalar value except for \r and \n, and also makes (?m:^) and
  (?m:$) match after and before both \r and \n, respectively, but never
  between a \r and \n.
• RegexBuilder::line_terminator was added to further customize the line
  terminator used by (?m:^) and (?m:$) to be any arbitrary byte.
• The std Cargo feature is now actually optional. That is, the regex crate
  can be used without the standard library.
• Because regex 1.9 may make binary size and compile times even worse, a
  new experimental crate called regex-lite has been published. It prioritizes
  binary size and compile times over functionality (like Unicode) and
  performance. It shares no code with the regex crate.

New features:

• FEATURE #​244:
  One can opt into CRLF mode via the R flag.
  e.g., (?mR:$) matches just before \r\n.
• FEATURE #​259:
  Multi-pattern searches with offsets can be done with regex-automata 0.3.
• FEATURE #​476:
  std is now an optional feature. regex may be used with only alloc.
• FEATURE #​644:
  RegexBuilder::line_terminator configures how (?m:^) and (?m:$) behave.
• FEATURE #​675:
  Anchored search APIs are now available in regex-automata 0.3.
• FEATURE #​824:
  Add new Captures::extract method for easier capture group access.
• FEATURE #​961:
  Add regex-lite crate with smaller binary sizes and faster compile times.
• FEATURE #​1022:
  Add TryFrom implementations for the Regex type.

Performance improvements:

• PERF #​68:
  Added a one-pass DFA engine for faster capture group matching.
• PERF #​510:
  Inner literals are now used to accelerate searches, e.g., \w+@​\w+ will scan
  for @.
• PERF #​787,
  PERF #​891:
  Makes literal optimizations apply to regexes of the form \b(foo|bar|quux)\b.

(There are many more performance improvements as well, but not all of them have
specific issues devoted to them.)

Bug fixes:

• BUG #​429:
  Fix matching bugs related to \B and inconsistencies across internal engines.
• BUG #​517:
  Fix matching bug with capture groups.
• BUG #​579:
  Fix matching bug with word boundaries.
• BUG #​779:
  Fix bug where some regexes like (re)+ were not equivalent to (re)(re)*.
• BUG #​850:
  Fix matching bug inconsistency between NFA and DFA engines.
• BUG #​921:
  Fix matching bug where literal extraction got confused by $.
• BUG #​976:
  Add documentation to replacement routines about dealing with fallibility.
• BUG #​1002:
  Use corpus rejection in fuzz testing.

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