build(deps): bump slab from 0.4.2 to 0.4.3

Bumps [slab](https://github.com/tokio-rs/slab) from 0.4.2 to 0.4.3.
- [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/v0.4.2...v0.4.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Cargo.lock

@@ -1640,9 +1640,9 @@ checksum = "cbce6d4507c7e4a3962091436e56e95290cb71fa302d0d270e32130b75fbff27"
 
 [[package]]
 name = "slab"
-version = "0.4.2"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
+checksum = "f173ac3d1a7e3b28003f40de0b5ce7fe2710f9b9dc3fc38664cebee46b3b6527"
 
 [[package]]
 name = "smallvec"