build(deps): bump slab from 0.4.5 to 0.4.6 (#1583)

Bumps [slab](https://github.com/tokio-rs/slab) from 0.4.5 to 0.4.6.
- [Release notes](https://github.com/tokio-rs/slab/releases)
- [Changelog](https://github.com/tokio-rs/slab/blob/master/CHANGELOG.md)
- [Commits](tokio-rs/slab@v0.4.5...v0.4.6)

---
updated-dependencies:
- dependency-name: slab
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

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

Cargo.lock

@@ -2266,9 +2266,9 @@ dependencies = [
 
 [[package]]
 name = "slab"
-version = "0.4.5"
+version = "0.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9def91fd1e018fe007022791f865d0ccc9b3a0d5001e01aabb8b40e46000afb5"
+checksum = "eb703cfe953bccee95685111adeedb76fabe4e97549a58d16f03ea7b9367bb32"
 
 [[package]]
 name = "smallvec"