libceed build targets wrong architecture

The Spack environment in the x86_64 cuda 80 image targets x86_64_v3, but we see:

 objdump -d $(spack location -i libceed)/lib/libceed.so | grep -m5 -E 'zmm|k[0-7],|vpternlog|vpermt2|evex'
   11250:       62 f1 fd 48 10 bc 30    vmovupd 0x8(%rax,%rsi,1),%zmm7
   1125b:       62 f1 c5 48 59 3c 31    vmulpd (%rcx,%rsi,1),%zmm7,%zmm7
   11284:       62 f3 fd 48 1b f9 01    vextractf64x4 $0x1,%zmm7,%ymm1
   11412:       62 f2 fd 48 19 f0       vbroadcastsd %xmm0,%zmm6
   11420:       62 f1 fd 48 10 8c 30    vmovupd 0x8(%rax,%rsi,1),%zmm1

...indicating it was built for AVX-512. Possibly the configure process detected the actual architecture of the build runner and ignored the arch spec that should have been passed through the Spack package.

This results in an 'illegal instruction' error from the libceed test on 'athena' which only provides ZEN2 compatibility.

The libceed-cuda test has been disabled until this can be resolved.

Start with the Spack environment and package configuration used by the x86_64 cuda 80 image, then inspect how the architecture spec reaches the configure process. Reproduce the objdump check and run the libceed test on the athena-compatible target; done means the library no longer emits AVX-512 instructions and the test passes without illegal-instruction failures. Keep the disabled libceed-cuda test in view.