Remove redundant dead_code check suppressions #369

Job	Run time
build with wasm-pack	2m 57s
Check License Header	2m 23s
cargo check	12m 30s
Check cargo fmt	41s
cargo test (macos)	14m 5s
cargo test (macos-aarch64)	10m 46s
Verify MSRV (Min Supported Rust Version)	9m 9s
Verify Vendored Code	1m 0s
cargo test (win64)	1h 10m 54s
cargo test datafusion-cli (amd64)	4m 8s
cargo test (amd64)	11m 47s
cargo doc	5m 2s
cargo test doc (amd64)	17m 33s
cargo examples (amd64)	14m 24s
Run sqllogictest with Postgres runner	3m 45s
clippy	6m 29s
check Cargo.toml formatting	2m 49s
verify benchmark results (amd64)	13m 7s
check configs.md and ***_functions.md is up-to-date	3m 28s
cargo test pyarrow (amd64)	2m 56s
cargo test hash collisions (amd64)	28m 56s
	3h 58m 49s

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