Remove noqa:S101 from production code

[Lee-W]

Why

during reviewing #70338, I found out we introduced assert into production code. according to https://github.com/apache/airflow/blob/main/contributing-docs/05_pull_requests.rst#don-t-use-asserts-outside-tests, we do not want this.

What

use if TYPE_CHECKING as what we did elsewhere

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• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst, in airflow-core/newsfragments. You can add this file in a follow-up commit after the PR is created so you know the PR number.

[shahar1]

Good catch!