AIP-83 Restore uniqueness constraint on logical date and make logical date nullable

[vatsrahul1001]

Closes: #46187

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[vatsrahul1001]

Few tests are failing looking into it

[vatsrahul1001]

Failing test cases will require change in backfill reprocess behaviour, I have create PR which will fix these failing tests

[uranusjr]

What’s the order we should merge the two PRs? Tests are not passing on this one, but the other PR needs this to be merged first.

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Edit: Talked to Rahul, this should be made greeen and go in first.

[Lee-W]

Suggested change

	or (
	task.start_date is None
	or (self.logical_date is not None and task.start_date <= self.logical_date)
	)
	and (
	task.end_date is None
	or (self.logical_date is not None and self.logical_date <= task.end_date)
	)
	or (
	task.start_date is None
	or self.logical_date is None
	or task.start_date <= self.logical_date
	)
	and (task.end_date is None or self.logical_date is None or self.logical_date <= task.end_date)

[Lee-W]

I suspect this "might" be the correct condition.

[vatsrahul1001]

Yes this one is correct. Thanks @Lee-W

[vatsrahul1001]

What’s the order we should merge the two PRs? Tests are not passing on this one, but the other PR needs this to be merged first.

--

Edit: Talked to Rahul, this should be made greeen and go in first.

@uranusjr Fixed failing tests now only failing tests are now related to backfill test_reprocess_behavior which are fixed in #46295 .