removed parse_expr in ntile #50

Job	Run time
cargo check	8m 3s
cargo test (macos)	11m 36s
Check cargo fmt	44s
build with wasm-pack	2m 43s
cargo test (macos-aarch64)	12m 8s
Verify Vendored Code	52s
cargo test (win64)	54m 29s
Verify MSRV (Min Supported Rust Version)	8m 12s
cargo test datafusion-cli (amd64)	4m 11s
cargo examples (amd64)	14m 9s
cargo test hash collisions (amd64)	17m 19s
clippy	5m 48s
check configs.md and ***_functions.md is up-to-date	2m 59s
check Cargo.toml formatting	2m 55s
cargo doc	4m 12s
cargo test (amd64)	11m 34s
cargo test doc (amd64)	15m 23s
Run sqllogictest with Postgres runner	3m 41s
cargo test pyarrow (amd64)	3m 56s
verify benchmark results (amd64)	12m 9s
	3h 17m 3s

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