Update afl requirement from =0.11.1 to =0.12.0

Updates the requirements on [afl](https://github.com/rust-fuzz/afl.rs) to permit the latest version.
- [Release notes](https://github.com/rust-fuzz/afl.rs/releases)
- [Changelog](https://github.com/rust-fuzz/afl.rs/blob/master/CHANGES.md)
- [Commits](rust-fuzz/afl.rs@0.11.1...0.12.0)

---
updated-dependencies:
- dependency-name: afl
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

test-fuzz/Cargo.toml

@@ -10,7 +10,7 @@ license = "MIT OR Apache-2.0"
 repository = "https://github.com/trailofbits/test-fuzz"
 
 [dependencies]
-afl = "=0.11.1"
+afl = "=0.12.0"
 serde = "1.0.136"
 
 internal = { path = "../internal", package = "test-fuzz-internal", version = "=2.0.1" }