deps: update libflate requirement from 1.0.0 to 2.1.0

Updates the requirements on [libflate](https://github.com/sile/libflate) to permit the latest version.
- [Release notes](https://github.com/sile/libflate/releases)
- [Commits](sile/libflate@1.0.0...2.1.0)

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

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

sprs-benches/Cargo.toml

@@ -16,7 +16,7 @@ pyo3 = { version = "0.18.3", features = ["auto-initialize"] }
 cc = "1.0.52"
 reqwest = { version="0.11.16", features=["blocking"], optional=true }
 tar = { version="0.4.26", optional=true }
-libflate = { version="1.0.0", optional=true }
+libflate = { version="2.1.0", optional=true }
 
 [features]
 default = []