Rust

minor: remove unused conversion #1089

Job	Run time
build with wasm-pack	1m 58s
Check cargo fmt	41s
cargo check	6m 30s
cargo test (mac)	12m 23s
Verify Vendored Code	46s
cargo test (win64)	3h 10m 45s
Verify MSRV	5m 57s
cargo test doc (amd64)	9m 26s
cargo examples (amd64)	6m 33s
check Cargo.toml formatting	1m 23s
clippy	4m 3s
cargo test hash collisions (amd64)	8m 23s
cargo doc	3m 5s
cargo test (amd64)	8m 47s
cargo test datafusion-cli (amd64)	3m 0s
cargo test pyarrow (amd64)	2m 11s
Run sqllogictest with Postgres runner	3m 1s
verify benchmark results (amd64)	9m 28s
check configs.md is up-to-date	2m 20s
	4h 40m 40s

Provide feedback