Not relocatable

HostCPUFeatures is in its current form, not relocatable; it bakes into its cache file which current CPU architecture is being used.

This is causing segmentation faults and aborts on GHA. Apparently a newer generation of runners with avx512 has been deployes causing
a mix of runners being used and caches being poisoned with wrong information.

The failure looks like this in it's most friendly form:

```
┌ Warning: Runtime invalidation was disabled, but the CPU info is out-of-date.
│ Will continue with incorrect CPU feature flag: -avx512dq.
└ @ HostCPUFeatures ~/.julia/packages/HostCPUFeatures/ZTXz4/src/cpu_info.jl:56
[ Info: You just called `trixi_include`. Julia may now compile the code, please be patient.
LLVM ERROR: Do not know how to split the result of this operator!

[2910] signal (6.-6): Aborted
in expression starting at /home/runner/work/Trixi.jl/Trixi.jl/examples/tree_2d_dgsem/elixir_euler_ec.jl:47
```

and like this

```
[ Info: Testset elixir_euler_double_mach_amr.jl finished in 10.883282604000001 seconds.
WARNING: replacing module TrixiTestModule.
════════════════════════════════════════════════════════════════════════════════════════════════════
/home/runner/work/Trixi.jl/Trixi.jl/examples/p4est_2d_dgsem/elixir_euler_supersonic_cylinder.jl
Package Trixi errored during testing (received signal: 6)
```

x-ref: https://github.com/trixi-framework/Trixi.jl/pull/2791