Weekly cargo update of fuzzing dependencies (#744)

Automation to keep dependencies in the fuzzing `Cargo.lock` current.

The following is the output from `cargo update`:

```txt
     Locking 8 packages to latest compatible versions
    Updating cc v1.2.14 -> v1.2.15
    Updating either v1.13.0 -> v1.14.0
    Updating libc v0.2.169 -> v0.2.170
    Updating log v0.4.25 -> v0.4.26
    Updating serde v1.0.217 -> v1.0.218
    Updating serde_derive v1.0.217 -> v1.0.218
    Updating serde_json v1.0.138 -> v1.0.139
    Updating unicode-ident v1.0.16 -> v1.0.17
note: pass `--verbose` to see 1 unchanged dependencies behind latest
```

Co-authored-by: github-actions <[email protected]>

Author: obi1kenobi