nixos/all-tests: Fix typo

}:

# The return value of this function will be an attrset with arbitrary depth and

# the `anything` returned by callTest at its test leafs.

# the `anything` returned by callTest at its test leaves.

# The tests not supported by `system` will be replaced with `{}`, so that

# `passthru.tests` can contain links to those without breaking on architectures

# where said tests are unsupported.