[FEAT] - figure out if test_bitcoin conditional should check for Darwin

### Describe the Problem

it's like this in the packageinstall step:

```
if [ "${TARGET_KERNEL}" = 'Darwin' ] && [ "${TARGET_ARCHITECTURE}" = 'arm64' ] &&
! is_arm64_test_bitcoin_signed "${target_bitcoin_version}"; then
```

### Describe the Solution

See if we should also only sign packages if it's Darwin

### Optional Additional Details

_No response_