[Pallas] Fix some sus tests, make them faster
1) These started failing when they got moved! This is because hypothesis uses a hash of the test to make its cases/seed how it samples, and these tests had conditions that were not being checked.
2) These tests took upwards of 3 minutes to run due to combinations and large shapes, use sharded hypothesis to make this take ~20s.
PiperOrigin-RevId: 783005553