Rust

Fix check_not_null_constraints null detection #282

Job	Run time
build with wasm-pack	2m 41s
Check cargo fmt	55s
cargo test (macos-aarch64)	6m 56s
cargo test (macos)	8m 36s
cargo check	11m 4s
Verify MSRV (Min Supported Rust Version)	8m 34s
Verify Vendored Code	55s
cargo test (win64)	30m 59s
cargo test datafusion-cli (amd64)	3m 58s
cargo examples (amd64)	14m 9s
cargo doc	4m 9s
cargo test (amd64)	10m 39s
cargo test doc (amd64)	15m 28s
Run sqllogictest with Postgres runner	3m 45s
verify benchmark results (amd64)	12m 13s
check Cargo.toml formatting	2m 50s
clippy	5m 40s
check configs.md and ***_functions.md is up-to-date	2m 55s
cargo test hash collisions (amd64)	17m 19s
cargo test pyarrow (amd64)	2m 51s
	2h 46m 36s

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