treewide: Remove more is_ssa asserts

treewide: Remove more is_ssa asserts

Stuff Coccinelle missed.

   sed -i -e '/assert(.*\.is_ssa)/d' $(git grep -l is_ssa)
   sed -i -e '/ASSERT.*\.is_ssa)/d' $(git grep -l is_ssa)

+ a manual fixup to restore the assert for parallel copy lowering.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24432>