build: Bump toml_datetime from 0.6.6 to 0.6.8 in /fuzz

Bumps [toml_datetime](https://github.com/toml-rs/toml) from 0.6.6 to 0.6.8.
- [Commits](https://github.com/toml-rs/toml/compare/toml_datetime-v0.6.6...toml_datetime-v0.6.8)

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

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

fuzz/Cargo.lock

@@ -885,9 +885,9 @@ dependencies = [
 
 [[package]]
 name = "toml_datetime"
-version = "0.6.6"
+version = "0.6.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4badfd56924ae69bcc9039335b2e017639ce3f9b001c393c1b2d1ef846ce2cbf"
+checksum = "0dd7358ecb8fc2f8d014bf86f6f638ce72ba252a2c3a2572f2a795f1d23efb41"
 
 [[package]]
 name = "toml_edit"