Remove compiler from hipblas-common spec

[tdrwenski]

Encountered this issue when updating Quandary to newer radiuss-spack-configs and Spack versions. I also manually tested the below on tioga with Spack 1.1.0. The compiler in the spec used to work with Spack 1.0.2 but does not with 1.1.0. But the hipblas-common spack package actually does not depend on c/cxx so I think this is the correct fix.

Before fix:

[drwenski1@tioga11]~/projects/radiuss-spack-configs% spack env activate toss_4_x86_64_ib_cray 
[drwenski1@tioga11]~/projects/radiuss-spack-configs% spack spec -I hipblas-common@6.4.3 
==> Error: failed to concretize `hipblas-common@6.4.3` for the following reasons:
     1. Cannot build hipblas-common, since it is configured `buildable:false` and no externals satisfy the request

After fix:

[drwenski1@tioga11]~/projects/radiuss-spack-configs% spack spec -I hipblas-common@6.4.3     
[e]  hipblas-common@6.4.3 build_system=cmake build_type=Release generator=make platform=linux os=rhel8 target=x86_64 

[tdrwenski]

The downside of this Spack change is that I now have to specify ^hiblas-common@version here to ensure I get a matching version with hipblas/ hip, so maybe there is something that could be improved in that Spack package for hipblas-common...

[adrienbernede]

Interesting issue. So, if I understand correctly, the concretization issue comes from us enforcing a compiler dependency on a package that has none. But when removing the compiler, we lack a constraint to enforce coherency between the compiler / software stack version and the external package version...

I feel like we should be able to set a requirement in the packages.yaml to keep that constraint without adding an imaginary dependency on the compiler.