TASK: Adjustments for ghc-srpm-macros removal

[fweimer-rh]

The ghc-srpm-macros package is no longer installed as part of the SRPM buildroot, so more GHC-related packages will fail to build. This shouldn't be a problem because GHC (under any of its package names) is not expected to be part of ELN, but there have been attempts to build it in the past.

[yselkowitz]

Ack, a possible issue wrt ELN Extras packages has already been raised in #187 and will be addressed there. In ELN proper though, ghc is not wanted and has already been removed for some time.