Add argument to ci for test threads and build jobs #55968

Job	Run time
miri	12m 53s
build (windows-latest)	14m 13s
build (ubuntu-latest)	8m 13s
check-bevy-internal-imports	4s
check-doc	12m 37s
check-missing-examples-in-docs	36s
ci	4m 38s
run-examples-macos-metal	7m 47s
toml	1m 58s
build (macos-latest)	5m 56s
typos	7s
check-missing-features-in-docs	40s
markdownlint	1m 10s
check-compiles-no-std	2m 16s
check-compiles	7m 37s
build-wasm-atomics	2m 10s
msrv	1m 42s
build-wasm	1m 46s
	1h 26m 23s

Provide feedback