Bump syn from 2.0.90 to 2.0.91 in /src/_bcrypt (#940)

Bumps [syn](https://github.com/dtolnay/syn) from 2.0.90 to 2.0.91.
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](https://github.com/dtolnay/syn/compare/2.0.90...2.0.91)

---
updated-dependencies:
- dependency-name: syn
  dependency-type: indirect
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/_bcrypt/Cargo.lock

@@ -299,9 +299,9 @@ checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
 [[package]]
 name = "syn"
-version = "2.0.90"
+version = "2.0.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "919d3b74a5dd0ccd15aeb8f93e7006bd9e14c295087c9896a110f490752bcf31"
+checksum = "d53cbcb5a243bd33b7858b1d7f4aca2153490815872d86d955d6ea29f743c035"
 dependencies = [
  "proc-macro2",
  "quote",