build: bump syn from 1.0.78 to 1.0.80 in /fuzz

Bumps [syn](https://github.com/dtolnay/syn) from 1.0.78 to 1.0.80.
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](https://github.com/dtolnay/syn/compare/1.0.78...1.0.80)

---
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

@@ -586,9 +586,9 @@ checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 
 [[package]]
 name = "syn"
-version = "1.0.78"
+version = "1.0.80"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4eac2e6c19f5c3abc0c229bea31ff0b9b091c7b14990e8924b92902a303a0c0"
+checksum = "d010a1623fbd906d51d650a9916aaefc05ffa0e4053ff7fe601167f3e715d194"
 dependencies = [
  "proc-macro2",
  "quote",