[misc] Get rid of pass statement in conditions

[Taragolis]

A minor change logic in conditions with empty block in it

[uranusjr]

I kind of like the old code actually, it’s a little easier to reason with, but that may be subjective.

[Taragolis]

I revisit to current code and also thought you right and XOR operation actually confuse mypy.
I would revert this changes and add comment to empty block.

[XD-DENG]

Agree with @uranusjr on this one

[potiuk]

Agree. The first one is more readable. I think it's not necesary True that "shorter == more readable" . I for example prefer to write classic nested for loop instead of nested for comprehension because I find it much better expressing the intention even if the latter is one-liner.

But in this case I think we have nice util that might make it even more readable - we have airflow.utils.helpers.exactly_one (added long time enough to pass >=2.3) and we could use that one making it most readable (even if not that efficient but in this case micro-optimisaatattion might be premature).

[Taragolis]

Return to initial variant. Just add short comments and tests.

Unfortunetly airflow.utils.helpers.exactly_one cannot use in this case because first argument (as well as second) for check would be Iterable

[potiuk]

Damn

[Taragolis]

This helper would be useful in another places

The comments were addressed :)