Remove MSVC's RSP meddling in `set_up_shared_memory`

[danbugs]

In set_up_shared_memory, for supporting PE files, we needed to subtract 0x28 from our RSP to give the called 'main' function the appearance that the RSP was 16 byte aligned before the 'call' that calls main. W/ the removal of PE files, this should no longer be needed, but, for some reason, the multiple_parameters from sandbox_host_tests fails when running w/ the C guest.

To repro, remove the 0x28 subtraction and run:

GUEST="c" cargo test -p hyperlight-host  --profile=dev --test 'sandbox_host_tests'

[simongdavies]

see https://wiki.osdev.org/Calling_Conventions SystemV ABI on x86_64 also requires 16 byte alignment, so I am not sure that we can get rid of this.