fix: remove child meta in build field meta #28

Job	Run time
Check cargo fmt	38s
cargo check	4m 8s
cargo test (mac)	6m 41s
Verify Vendored Code	46s
cargo test (win64)	9m 1s
cargo examples (amd64)	4m 55s
cargo test doc (amd64)	8m 53s
clippy	2m 14s
cargo doc	1m 51s
cargo test hash collisions (amd64)	6m 31s
check Cargo.toml formatting	1m 26s
cargo test (amd64)	6m 57s
cargo test datafusion-cli (amd64)	2m 49s
Run sqllogictest with Postgres runner	3m 8s
cargo test pyarrow (amd64)	34s
verify benchmark results (amd64)	20m 52s
check configs.md is up-to-date	2m 24s
	1h 23m 48s

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