chore(deps): bump syn in the cargo-dependencies group (#25)

Bumps the cargo-dependencies group with 1 update: [syn](https://github.com/dtolnay/syn).


Updates `syn` from 2.0.87 to 2.0.90
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](dtolnay/syn@2.0.87...2.0.90)

---
updated-dependencies:
- dependency-name: syn
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: cargo-dependencies
...

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

focusable-derive/Cargo.toml

@@ -18,6 +18,6 @@ proc-macro = true
 
 [dependencies]
 quote = "1.0.37"
-syn = "2.0.87"
+syn = "2.0.90"
 proc-macro2 = "1.0.92"
 tracing = { version = "0.1.41", optional = true }