Fix repopendingperms tests

Created by: varsanojidan

Fixing a flaky test, basically the implementation changed from using roaring.BitMap to just builtin Go maps, what ended up happening was that because go doesn't guarantee order when iterating over keys in a map, sometimes the tests would fail when checking for hard equality. I moved it to check for equality of sets instead.

From what I can tell the ordering of the permissions being returned doesn't actually make a difference, but the tests were checking for it, if my assumption isn't correct please lmk.

Test plan

Unneeded, fixing flakey test.