Update reqwest requirement from 0.11 to 0.12 (AFLplusplus#2196)

Updates the requirements on [reqwest](https://github.com/seanmonstar/reqwest) to permit the latest version.
- [Release notes](https://github.com/seanmonstar/reqwest/releases)
- [Changelog](https://github.com/seanmonstar/reqwest/blob/master/CHANGELOG.md)
- [Commits](seanmonstar/reqwest@v0.11.0...v0.12.4)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

libafl/Cargo.toml

@@ -136,7 +136,7 @@ agpl = ["nautilus"]
 nautilus = ["grammartec", "std", "serde_json/std"]
 
 [build-dependencies]
-reqwest = { version = "0.11", features = ["blocking"], optional = true }
+reqwest = { version = "0.12", features = ["blocking"], optional = true }
 rustversion = "1.0"
 zip = { version = "0.6", optional = true }