Bump slab from 0.4.6 to 0.4.7 (#125)

Bumps [slab](https://github.com/tokio-rs/slab) from 0.4.6 to 0.4.7.
- [Release notes](https://github.com/tokio-rs/slab/releases)
- [Changelog](https://github.com/tokio-rs/slab/blob/master/CHANGELOG.md)
- [Commits](https://github.com/tokio-rs/slab/compare/v0.4.6...v0.4.7)

---
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

@@ -1675,9 +1675,12 @@ checksum = "43b2853a4d09f215c24cc5489c992ce46052d359b5109343cbafbf26bc62f8a3"
 
 [[package]]
 name = "slab"
-version = "0.4.6"
+version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb703cfe953bccee95685111adeedb76fabe4e97549a58d16f03ea7b9367bb32"
+checksum = "4614a76b2a8be0058caa9dbbaf66d988527d86d003c11a94fbd335d7661edcef"
+dependencies = [
+ "autocfg",
+]
 
 [[package]]
 name = "smallvec"