Update criterion requirement from 0.7 to 0.8 (#64)

Updates the requirements on [criterion](https://github.com/criterion-rs/criterion.rs) to permit the latest version.
- [Release notes](https://github.com/criterion-rs/criterion.rs/releases)
- [Changelog](https://github.com/criterion-rs/criterion.rs/blob/master/CHANGELOG.md)
- [Commits](criterion-rs/criterion.rs@criterion-plot-v0.7.0...criterion-plot-v0.7.0)

---
updated-dependencies:
- dependency-name: criterion
  dependency-version: 0.7.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Cargo.toml

@@ -25,7 +25,7 @@ overflow-checks = true
 [dev-dependencies]
 proptest = "1"
 rand = "0.9"
-criterion = { version = "0.7", default-features = false }
+criterion = { version = "0.8", default-features = false }
 
 [features]
 unstable = []