Add support for static nix-tools #1972

Job	Run time
build-extra-hackages	6s
cabal	13s
cabal-doExactConfig	9s
check-materialization-concurrency	18s
check-path-support	10s
closure-size	5s
docs	1m 13s
haskell-nix-roots-do-not-require-IFDs	5s
hix	39s
hix-cabal	20s
hydra-ifdLevel-0-and-1	11s
hydra-ifdLevel-2	8s
hydra-ifdLevel-3-and-ghc-8-10	7s
hydra-ifdLevel-3-and-ghc-9-2	6s
hydra-ifdLevel-3-and-not-ghc-8-10-or-9-2	7s
hydra-without-remote-builders	8s
maintainer-scripts	7s
multi-target	13s
nix-build	22s
nix-tools	5s
plan-extra-hackages	5s
runghc	7s
shellFor-hoogle	8s
shellFor-multiple-package	10s
shellFor-not-depends	14s
shellFor-single-package	13s
tests-benchmarks	6s
unit-tests	4s
update-docs	7s
	6m 6s

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