Add ghc 9.6.7 #3036

Job	Run time
unit-tests	6s
nix-build	4m 39s
cabal	12s
runghc	18s
cabal-doExactConfig	11s
multi-target	42s
tests-benchmarks	15s
build-extra-hackages	7s
hix	4m 44s
maintainer-scripts	9s
plan-extra-hackages	6s
shellFor-hoogle	12s
shellFor-multiple-package	17s
shellFor-not-depends	16s
check-path-support	5s
shellFor-single-package	17s
check-materialization-concurrency	20s
closure-size	3s
docs	35s
haskell-nix-roots-do-not-require-IFDs	13s
hydra-ifdLevel-0-and-1	3m 30s
hydra-ifdLevel-2	12m 12s
hydra-ifdLevel-3	30m 10s
update-docs	6s
hix-cabal	8s
hydra-without-remote-builders-ghc9101	2m 34s
hydra-without-remote-builders-ghc966	7s
nix-tools	13s
	1h 2m 47s

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