build(deps): update hashbrown requirement from 0.8 to 0.9 (paritytech…

…#456)

Updates the requirements on [hashbrown](https://github.com/rust-lang/hashbrown) to permit the latest version.
- [Release notes](https://github.com/rust-lang/hashbrown/releases)
- [Changelog](https://github.com/rust-lang/hashbrown/blob/master/CHANGELOG.md)
- [Commits](rust-lang/hashbrown@v0.8.0...v0.9.1)

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

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

parity-util-mem/Cargo.toml

@@ -19,7 +19,7 @@ cfg-if = "1.0.0"
 dlmalloc = { version = "0.2.1", features = ["global"], optional = true }
 wee_alloc = { version = "0.4.5", optional = true }
 lru = { version = "0.6", optional = true }
-hashbrown = { version = "0.8", optional = true }
+hashbrown = { version = "0.9", optional = true }
 mimalloc = { version = "0.1.18", optional = true }
 libmimalloc-sys = { version = "0.1.14", optional = true }
 parity-util-mem-derive = { path = "derive", version = "0.1" }