Rust

Improve `case` expr constant handling for when `<scalar>` #36978

Job	Run time
linux build test	4m 33s
Check License Header	2m 21s
build with wasm-pack	3m 45s
Check cargo fmt	42s
cargo test (macos-aarch64)	14m 33s
Verify Vendored Code	53s
Verify MSRV (Min Supported Rust Version)	11m 8s
cargo check functions	2m 16s
cargo check datafusion	5m 40s
check Cargo.toml formatting	3m 6s
clippy	7m 47s
check configs.md and ***_functions.md is up-to-date	4m 23s
cargo check no default features	10m 3s
cargo doc	6m 0s
cargo test (amd64)	12m 52s
cargo test datafusion-cli (amd64)	5m 42s
cargo test doc (amd64)	19m 10s
cargo examples (amd64)	16m 29s
Run sqllogictest with Postgres runner	5m 29s
cargo test pyarrow (amd64)	3m 16s
verify benchmark results (amd64)	8m 52s
	2h 29m 0s

Provide feedback