Bump regex from 1.7.3 to 1.8.1

[dependabot]

Bumps regex from 1.7.3 to 1.8.1.

Changelog

Sourced from regex's changelog.

1.8.1 (2023-04-21)

This is a patch release that fixes a bug where a regex match could be reported where none was found. Specifically, the bug occurs when a pattern contains some literal prefixes that could be extracted and an optional word boundary in the prefix.

Bug fixes:

• [BUG #981](rust-lang/regex#981): Fix a bug where a word boundary could interact with prefix literal optimizations and lead to a false positive match.

1.8.0 (2023-04-20)

This is a sizeable release that will be soon followed by another sizeable release. Both of them will combined close over 40 existing issues and PRs.

This first release, despite its size, essentially represent preparatory work for the second release, which will be even bigger. Namely, this release:

• Increases the MSRV to Rust 1.60.0, which was released about 1 year ago.
• Upgrades its dependency on aho-corasick to the recently release 1.0 version.
• Upgrades its dependency on regex-syntax to the simultaneously released 0.7 version. The changes to regex-syntax principally revolve around a rewrite of its literal extraction code and a number of simplifications and optimizations to its high-level intermediate representation (HIR).

The second release, which will follow ~shortly after the release above, will contain a soup-to-nuts rewrite of every regex engine. This will be done by bringing regex-automata into this repository, and then changing the regex crate to be nothing but an API shim layer on top of regex-automata's API.

These tandem releases are the culmination of about 3 years of on-and-off work that began in earnest in March 2020.

Because of the scale of changes involved in these releases, I would love to hear about your experience. Especially if you notice undocumented changes in behavior or performance changes (positive or negative).

Most changes in the first release are listed below. For more details, please see the commit log, which reflects a linear and decently documented history of all changes.

New features:

... (truncated)

Commits

• 4e29fce 1.8.1
• 8a7cb64 deps: bump regex-syntax to 0.7.1
• 31c8452 regex-syntax-0.7.1
• 960aade changelog: 1.8.1
• f003d72 impl: fix prefix literal matching bug
• 93316a3 doc: update MSRV in README
• 070374f release: 1.8.0
• a73c61c fuzz: get rid of 'named-profiles' feature
• 7cd75d2 changelog: tweaks to 1.8 release entry
• 33898de syntax: fix bug in new alternation literal analysis
• Additional commits viewable in compare view

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[DMRobertson]

Increases the MSRV to Rust 1.60.0, which was released about 1 year ago.

This is currently incompatible with our MSRV (1.58). If we want to land this, we could bump the MSRV as per https://matrix-org.github.io/synapse/latest/deprecation_policy.html.

[erikjohnston]

I'm personally in favour of not worrying too much about MSRV if we bump to a Rust version over a year old

[DMRobertson]

The team has a slight desire to do land this so that we don't find ourselves suddenly with a need to deal with this problem in the future if there was an urgent fix to this library; though there isn't anything in particular from this update that we want per se.

[dependabot]

A newer version of regex exists, but since this PR has been edited by someone other than Dependabot I haven't updated it. You'll get a PR for the updated version as normal once this PR is merged.

[clokep]

The team has a slight desire to do land this so that we don't find ourselves suddenly with a need to deal with this problem in the future if there was an urgent fix to this library; though there isn't anything in particular from this update that we want per se.

What's the next step here then? How do we make a decision?

[DMRobertson]

@dependabot rebase

[dependabot]

Looks like this PR has been edited by someone other than Dependabot. That means Dependabot can't rebase it - sorry!

If you're happy for Dependabot to recreate it from scratch, overwriting any edits, you can request @dependabot recreate.

[DMRobertson]

@dependabot recreate

[dependabot]

Superseded by #15769.