Add airflowctl tasks clear command

[FrankYang0529]

• Add airflowctl tasks clear <dag_id>.
• Add TasksOperations.clear in operations.py (POST /dags/{dag_id}/clearTaskInstances), from which the CLI command is auto-generated.
• Make generated bool flags follow the ClearTaskInstancesBody field defaults.
• Accept --task-ids as comma-separated ids or a JSON list of task_id / [task_id, map_index].
• Mark the core CLI command with @deprecated_for_airflowctl("airflowctl tasks clear") and register it in test_command_deprecations.py.

Add TasksOperations.clear() in operations.py calling POST /dags/{dag_id}/clearTaskInstances. airflowctl tasks clear is auto-generated from it. Bool flags of ClearTaskInstancesBody follow the datamodel field defaults: a bare tasks clear dry-runs, --no-dry-run actually clears, and --run-on-latest-version keeps its tri-state fallback semantics. --task-ids accepts comma-separated ids or a JSON list of task_id / [task_id, map_index].

• closes: [AIP-94] airflowctl tasks: add clear command #66176
• related: [AIP-94] airflowctl command migration #68402

---

Was generative AI tooling used to co-author this PR?

• Yes - Claude Code

---

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• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
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[henry3260]

reopen to trigger full ci test

[henry3260]

LGTM! need another pair of eyes

[Lee-W]

a few nits, but mostly good

[henry3260]

That's really nice! It will be merged when ci greens

[github-actions]

Backport failed to create: airflow-ctl/v0-1-test. View the failure log Run details

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
❌	airflow-ctl/v0-1-test

You can attempt to backport this manually by running:

cherry_picker 41613f2 airflow-ctl/v0-1-test

This should apply the commit to the airflow-ctl/v0-1-test branch and leave the commit in conflict state marking
the files that need manual conflict resolution.

After you have resolved the conflicts, you can continue the backport process by running:

cherry_picker --continue

If you don't have cherry-picker installed, see the installation guide.

[github-actions]

Backport failed to create: v3-3-test. View the failure log Run details

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
❌	v3-3-test

You can attempt to backport this manually by running:

cherry_picker 41613f2 v3-3-test

This should apply the commit to the v3-3-test branch and leave the commit in conflict state marking
the files that need manual conflict resolution.

After you have resolved the conflicts, you can continue the backport process by running:

cherry_picker --continue

If you don't have cherry-picker installed, see the installation guide.