Bump regex from 1.5.3 to 1.5.4

Bumps [regex](https://github.com/rust-lang/regex) from 1.5.3 to 1.5.4.
- [Release notes](https://github.com/rust-lang/regex/releases)
- [Changelog](https://github.com/rust-lang/regex/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-lang/regex/compare/1.5.3...1.5.4)

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.lock

@@ -484,9 +484,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.5.3"
+version = "1.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce5f1ceb7f74abbce32601642fcf8e8508a8a8991e0621c7d750295b9095702b"
+checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
 dependencies = [
  "aho-corasick",
  "memchr",

Cargo.toml

@@ -34,7 +34,7 @@ percent-encoding = "2.1.0"
 pulldown-cmark = "0.8.0"
 pulldown-cmark-to-cmark = "6.0.0"
 rayon = "1.5.0"
-regex = "1.5.3"
+regex = "1.5.4"
 serde_yaml = "0.8.17"
 slug = "0.1.4"
 snafu = "0.6.10"