Bring back compile_to_stencil_offthread #1097

Job	Run time
windows (debugmozjs, x86_64-pc-windows-msvc)	18m 58s
windows (debugmozjs, aarch64-pc-windows-msvc)	13m 54s
integrity	35s
windows (streams, x86_64-pc-windows-msvc)	17m 42s
android	9m 21s
windows (streams, aarch64-pc-windows-msvc)	14m 24s
linux (aarch64-unknown-linux-gnu)	13m 42s
linux (debugmozjs)	10m 12s
mac (debugmozjs, aarch64-apple-darwin, macos-14)	7m 19s
OpenHarmony build (aarch64-unknown-linux-ohos)	14m 55s
linux (streams)	6m 41s
mac (debugmozjs, x86_64-apple-darwin, macos-13)	17m 48s
mac (streams, aarch64-apple-darwin, macos-14)	6m 39s
linux (armv7-unknown-linux-gnueabihf)	12m 7s
mac (streams, x86_64-apple-darwin, macos-13)	16m 34s
Check version and publish release	0s
Verify release	0s
Result	1s
	3h 0m 52s

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