Replace serde_json with simd_json #6145

Job	Run time
Check	24s
coverage	9m 53s
test (beta)	1m 36s
test_all_features	12m 50s
test (stable)	1m 56s
test (windows)	5m 15s
Check if cbindgen runs cleanly for generating the C headers	8m 6s
Lints (beta)	14s
Lints (stable)	9s
test (macos)	1m 16s
minimum_rust_version	6m 36s
Publish (on tags, dry-run otherwise)	8m 25s
Run tests under wasm32-wasi	1m 20s
Check if wasm-pack builds a valid package for the sourmash crate	1m 20s
	59m 20s

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