classes/native: Propagate dependencies to outhash

Native task outputs are directly run on the build system during the build
after being built. Even if the output of a native recipe doesn't change, a
change in one of its dependencies may cause a change in the output it
generates (e.g. rpm output depends on the output of its dependent zstd
library).

This can cause poor interactions with hash equivalence, since this
recipe's output-changing dependency is "hidden" and downstream tasks only
see that this recipe has the same outhash and therefore is equivalent.
This can result in different output in different cases and issues with
reproducible builds in parcular (e.g. rpm compression changes for the same
content).

To resolve this, unhide the output-changing dependency by adding it's
unihash to this tasks outhash calculation. Unfortunately, we don't know
specifically know which dependencies are output-changing, so we have to
add all of them.

[YOCTO #14685]

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>