boards: posix: native_posix_64: Add sim: native

If one does not specify `simulation: native` in a `testcase.yaml` file,
then when trying to run tests with `native_posix_64` as the platform,
the `TestInstance.setup_handler` method in
`scripts/pylib/twister/twisterlib/testinstance.py` will not assign a
handler and one's tests will be marked as ran, but the test output
will all be of the form "... No status" since the test binary is built
but not ran.

Fixes #54605

Signed-off-by: Pete Dietl <petedietl@gmail.com>
1 file changed