build: Bump syn from 1.0.99 to 1.0.100 in /fuzz

Bumps [syn](https://github.com/dtolnay/syn) from 1.0.99 to 1.0.100.
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](https://github.com/dtolnay/syn/compare/1.0.99...1.0.100)

---
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

@@ -750,9 +750,9 @@ checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "syn"
-version = "1.0.99"
+version = "1.0.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "58dbef6ec655055e20b86b15a8cc6d439cca19b667537ac6a1369572d151ab13"
+checksum = "52205623b1b0f064a4e71182c3b18ae902267282930c6d5462c91b859668426e"
 dependencies = [
  "proc-macro2",
  "quote",