build(deps): update syn requirement from 1.0.14 to 2.0.55

Updates the requirements on [syn](https://github.com/dtolnay/syn) to permit the latest version.
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](dtolnay/syn@1.0.14...2.0.55)

---
updated-dependencies:
- dependency-name: syn
  dependency-type: direct:production
...

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

rlp-derive/Cargo.toml

@@ -12,7 +12,7 @@ rust-version = "1.56.1"
 proc-macro = true
 
 [dependencies]
-syn = "1.0.14"
+syn = "2.0.55"
 quote = "1.0.2"
 proc-macro2 = "1.0.8"