access: golang/crypto Write or Maintain access

[FiloSottile]

I'd like to be able to edit the title of PRs in the x/crypto GitHub repo (like golang/crypto#195), and I seem to not have that access. I don't remember what group grants that.

This is really due to #24887 and even more fundamentally due to #25359, but in the meantime I'd like not to go multiple rounds of review to explain to occasional contributors how to fix their commit messages for tiny fixes.

/cc @golang/release

[heschi]

Done.