build: bump syn from 1.0.87 to 1.0.88 in /fuzz

Bumps [syn](https://github.com/dtolnay/syn) from 1.0.87 to 1.0.88.
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](https://github.com/dtolnay/syn/compare/1.0.87...1.0.88)

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

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

fuzz/Cargo.lock

@@ -656,9 +656,9 @@ checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "syn"
-version = "1.0.87"
+version = "1.0.88"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e59d925cf59d8151f25a3bedf97c9c157597c9df7324d32d68991cc399ed08b"
+checksum = "ebd69e719f31e88618baa1eaa6ee2de5c9a1c004f1e9ecdb58e8352a13f20a01"
 dependencies = [
  "proc-macro2",
  "quote",