Bump libflate from 1.2.0 to 2.0.0 in /lang/rust (apache#2331)

* Bump libflate from 1.2.0 to 2.0.0 in /lang/rust

Bumps [libflate](https://github.com/sile/libflate) from 1.2.0 to 2.0.0.
- [Release notes](https://github.com/sile/libflate/releases)
- [Commits](sile/libflate@1.2.0...2.0.0)

---
updated-dependencies:
- dependency-name: libflate
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

* Enable "std" feature for libflate dependency

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* Simplify test code

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

---------

Signed-off-by: dependabot[bot] <support@github.com>
Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

lang/rust/avro/Cargo.toml

@@ -60,7 +60,7 @@ bzip2 = { default-features = false, version = "0.4.4", optional = true }
 crc32fast = { default-features = false, version = "1.3.2", optional = true }
 digest = { default-features = false, version = "0.10.7", features = ["core-api"] }
 lazy_static = { default-features = false, version = "1.4.0" }
-libflate = { default-features = false, version = "1.2.0" }
+libflate = { default-features = false, version = "2.0.0", features = ["std"] }
 log = { default-features = false, version = "0.4.19" }
 num-bigint = { default-features = false, version = "0.4.3" }
 regex = { default-features = false, version = "1.9.0", features = ["std", "perf"] }

lang/rust/avro_derive/tests/derive.rs

@@ -31,10 +31,7 @@ extern crate serde;
 #[cfg(test)]
 mod test_derive {
     use apache_avro::schema::{Alias, EnumSchema, RecordSchema};
-    use std::{
-        borrow::{Borrow, Cow},
-        sync::Mutex,
-    };
+    use std::{borrow::Cow, sync::Mutex};
 
     use super::*;
 
@@ -866,7 +863,7 @@ mod test_derive {
         // test serde with manual equality for mutex
         let test = serde(test);
         assert_eq!("hey", test.a);
-        assert_eq!(vec![42], *test.b.borrow().lock().unwrap());
+        assert_eq!(vec![42], *test.b.lock().unwrap());
         assert_eq!(Cow::Owned::<i32>(32), test.c);
     }