Add argument to ci for test threads and build jobs #55963

Job	Run time
miri	1s
build (windows-latest)	1s
build (ubuntu-latest)	1s
check-doc	1s
check-bevy-internal-imports	3s
check-missing-examples-in-docs	1s
build (macos-latest)	1s
ci	1s
run-examples-macos-metal	2s
toml	1s
typos	1s
check-missing-features-in-docs	1s
markdownlint	1m 4s
check-compiles	1s
check-compiles-no-std	1s
build-wasm	1s
build-wasm-atomics	1s
msrv	1s
	1m 24s

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