Add missing OpenDrain[IO] tests

[Finomnis]

• Add tests for OpenDrainIO
  • Added in #401
• Add missing test for OpenDrain

[jonas-schievink]

Thanks! Note that we don't run these tests during CI, so updating them for HAL changes isn't necessary.

bors r+

[Finomnis]

Thanks! Note that we don't run these tests during CI, so updating them for HAL changes isn't necessary.

bors r+

It's good practice, though ;)

[bors[bot]]

Build succeeded:

• ci