Update memmap2 requirement from 0.7.0 to 0.9.0

Updates the requirements on [memmap2](https://github.com/RazrFalcon/memmap2-rs) to permit the latest version.
- [Changelog](https://github.com/RazrFalcon/memmap2-rs/blob/master/CHANGELOG.md)
- [Commits](RazrFalcon/memmap2-rs@v0.7.0...v0.9.0)

---
updated-dependencies:
- dependency-name: memmap2
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Cargo.toml

@@ -27,7 +27,7 @@ ipnetwork = "0.20.0"
 log = "0.4"
 serde = { version = "1.0", features = ["derive"] }
 memchr = "2.4"
-memmap2 = { version = "0.7.0", optional = true }
+memmap2 = { version = "0.9.0", optional = true }
 
 [dev-dependencies]
 env_logger = "0.10"