Account for constant equivalence properties in union, tests #3822

Job	Run time
cargo test (macos)	7m 32s
cargo check	7m 51s
build with wasm-pack	2m 35s
cargo test (macos-aarch64)	8m 4s
cargo test (win64)	50m 37s
Check cargo fmt	42s
Verify MSRV (Min Supported Rust Version)	7m 13s
Verify Vendored Code	49s
cargo examples (amd64)	14m 0s
cargo test (amd64)	9m 59s
cargo test datafusion-cli (amd64)	4m 12s
check Cargo.toml formatting	2m 59s
clippy	5m 33s
check configs.md is up-to-date	2m 49s
cargo test hash collisions (amd64)	14m 50s
cargo doc	3m 54s
cargo test doc (amd64)	11m 25s
Run sqllogictest with Postgres runner	3m 39s
cargo test pyarrow (amd64)	2m 55s
verify benchmark results (amd64)	12m 20s
	2h 53m 58s

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