Bump GHC JS to 9.12 #1143

Job	Run time
fedora37	4m 21s
i386	2m 3s
build (ubuntu-24.04, 9.12)	3m 11s
build (ubuntu-24.04, 9.10)	1m 32s
redhat-ubi9	4m 29s
build (ubuntu-24.04, 9.8)	1m 8s
build (ubuntu-24.04, 9.6)	2m 30s
build (ubuntu-24.04, 9.4)	2m 15s
arm (arm32v7)	5m 6s
build (ubuntu-24.04, 9.2)	1m 33s
arm (arm64v8)	2m 22s
build (ubuntu-24.04, 9.0)	2m 4s
build (ubuntu-24.04, 8.10)	1m 59s
build (ubuntu-24.04, 8.8)	2m 0s
freebsd (self-hosted, FreeBSD, X64, 9.4)	1m 5s
build (ubuntu-24.04, 8.6)	2m 3s
freebsd (self-hosted, FreeBSD, X64, 9.6)	1m 3s
build (macOS-latest, 9.12)	4m 17s
build (macOS-latest, 9.10)	3m 25s
build (macOS-latest, 9.8)	3m 30s
build (macOS-latest, 9.6)	3m 21s
build (macOS-latest, 9.4)	3m 3s
build (macOS-latest, 9.2)	2m 22s
	1h 0m 42s

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