Update clickhouse requirement from 0.11 to 0.12

Updates the requirements on [clickhouse](https://github.com/loyd/clickhouse.rs) to permit the latest version.
- [Changelog](https://github.com/loyd/clickhouse.rs/blob/master/CHANGELOG.md)
- [Commits](ClickHouse/clickhouse-rs@v0.11.0...v0.12.0)

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

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

Cargo.toml

@@ -34,11 +34,11 @@ path = "examples/remove/main.rs"
 
 
 [dependencies]
-clickhouse = { version = "0.11", features = ["watch"] }
+clickhouse = { version = "0.12", features = ["watch"] }
 clickhouse-derive = { version = "0.1" }
 tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
 serde = { version = "1.0.196", features = ["derive"] }
 
 
 [dev-dependencies]
-clickhouse = { version = "0.11", features = ["test-util"] }
+clickhouse = { version = "0.12", features = ["test-util"] }