It seems that there was a regression. `build_config` no longer has an
`OUT_DIR` in it.
On way to mitigate it is to stop relying on it and just use `cwd` as dir
for the test binary to be placed in.

Release Notes:
- N/A

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Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>