Rename execution_date to logical_date across codebase

[sunank200]

Motivation

This PR renames execution_date to logical_date across the codebase. The shift towards logical_date helps move away from the limitations of execution_date, particularly with dynamic DAG runs and cases where multiple runs occur at the same time.

Key Changes

• Replaced all instances of execution_date with logical_date including models.
• Updated references in database models, templates, and functions.
• Removed unique constraints on execution_date in the database to allow multiple DAG runs with the same logical time.

How execution_date and logical_date Work

1. Logical date is equivalent to execution date: The two are just different names for the same value.
2. Timetable controls logical date: The logical date can be set to any value, not necessarily tied to the data interval's start or end.
3. Schedules dictate behavior: For value-based schedules (like cron), the logical date is set by the timetable class used.

Transitioning from execution_date

• Airflow 3.0 will fully remove execution_date.
• For uniquely identifying runs:
  • Use run_id for human-readable identifiers.
  • Use data_interval_start/data_interval_end for data partitioning in future.
  • id (auto-incremented) is recommended for ordering DAG runs.
• If your existing logic relies on execution_date, switch to using data_interval_start or data_interval_end for identifying time ranges.

Testing

• Updated unit tests to reflect the changes.

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[uranusjr]

This needs a news fragment. Rewording the above summary would work fine. See existing files in newsfragments (the significant ones) for some examples.

[uranusjr]

For templates, replace {{ ds }} with {{ data_interval_start | ds }}.

This should probably use logical_date for max compatibility. Also should mention ts (same rewrite).

Oh wait, we’re not removing those in this PR yet, so this should not be mentioned at all.