ghc.nix installs too many things by default

It seems that some unecessary tools are provisioned by ghc.nix

• Formatters are not required for GHC development (there is an ormolo override)
• Linters are not required for GHC development (hlint is listed as a system dependency)

Therefore support for them being provisioned should be removed from ghc.nix in order to simplify the maintenance.

These are all non-standard configurations which should be disabled by default

• withGrind is by default true
• withDtrace is by default true
• withGdb is by default true
• withDwarf is by default true
• withNuma is by default true
• withPerf is enabled by default

Running nix develop starts downloading a large number of dependencies which most developers will never need.