Rust

remove unnecessary computations #1685

Job	Run time
Check cargo fmt	40s
Check License Header	2m 28s
linux build test	4m 47s
cargo test (macos-aarch64)	8m 16s
build with wasm-pack	3m 46s
Verify Vendored Code	55s
Verify MSRV (Min Supported Rust Version)	11m 34s
cargo check no default features	10m 48s
cargo check datafusion	5m 32s
cargo doc	6m 17s
cargo check functions	2m 14s
cargo test datafusion-cli (amd64)	5m 24s
cargo test (amd64)	8m 49s
cargo test doc (amd64)	19m 13s
cargo examples (amd64)	16m 25s
check Cargo.toml formatting	3m 9s
clippy	2m 44s
check configs.md and ***_functions.md is up-to-date	4m 33s
Run sqllogictest with Postgres runner	5m 23s
cargo test pyarrow (amd64)	3m 31s
verify benchmark results (amd64)	8m 48s
	2h 15m 16s

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