* op-e2e: Always run subtests on the parent executor.

* op-e2e: Fix TestMixedWithdrawalValidity by not cancelling its own context.

Moves timeouts to be handled in helpers to reduce complexity of the test.

* op-e2e: Fix TestMixedWithdrawalValidity for fault proofs

* op-e2e: Evaluate test options for subtests

Ensures that tests are skipped correctly when using conditional options like UsesCannon even if not specified in the parent case.

Add InitParallel back to cannon tests so they can execute in parallel.