build: bump crossbeam from 0.8.3 to 0.8.4

Bumps [crossbeam](https://github.com/crossbeam-rs/crossbeam) from 0.8.3 to 0.8.4.
- [Release notes](https://github.com/crossbeam-rs/crossbeam/releases)
- [Changelog](https://github.com/crossbeam-rs/crossbeam/blob/master/CHANGELOG.md)
- [Commits](crossbeam-rs/crossbeam@crossbeam-0.8.3...crossbeam-0.8.4)

---
updated-dependencies:
- dependency-name: crossbeam
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Cargo.lock

@@ -45,7 +45,7 @@ clap_mangen = "0.2.12"
 color-eyre = "0.6.2"
 concolor = { version = "0.1.1", features = ["auto"] }
 console = "0.15.8"
-crossbeam = "0.8.3"
+crossbeam = "0.8.4"
 cursive = { version = "0.20.0", default-features = false, features = [
     "crossterm-backend",
 ] }