Rust

[MINOR] Replace null treatment with boolean for #10230 #7

Job	Run time
cargo test (win64)	36m 49s
build with wasm-pack	2m 16s
cargo check	3m 19s
cargo test (macos)	9m 20s
Check cargo fmt	41s
cargo test (macos-aarch64)	9m 20s
Verify MSRV (Min Supported Rust Version)	6m 34s
Verify Vendored Code	56s
cargo test (amd64)	10m 13s
clippy	4m 42s
cargo test datafusion-cli (amd64)	3m 38s
cargo doc	3m 45s
cargo test doc (amd64)	11m 30s
cargo examples (amd64)	11m 0s
Run sqllogictest with Postgres runner	3m 4s
cargo test pyarrow (amd64)	2m 33s
verify benchmark results (amd64)	10m 43s
check Cargo.toml formatting	2m 55s
cargo test hash collisions (amd64)	9m 51s
check configs.md is up-to-date	2m 39s
	2h 25m 48s

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