d/patches: remove empty and/or outdated patches

The `revert-twox-hash.dif` patch is no longer needed as a similar change
was merged upstream, which is included in this package as part of the
`sort` backport.

`bump-thread-local` is an empty file causing issues when using `gbp pq`,
and can be safely removed.

Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>