Mask Connection password in Task SDK

[roshanprabu]

Summary

airflow.sdk.definitions.connection.Connection (the Task SDK connection model used inside a running task in Airflow 3.x) masks extra fields via mask_secret(), but never masked the top-level password field, unlike the core ORM Connection. This meant secrets such as an Azure service principal secret (which maps to Connection.password) leaked into task logs unmasked whenever the connection was resolved through the Task SDK — e.g. when sourced from an AIRFLOW_CONN_* environment variable URI.

This adds the same mask_secret(self.password) / mask_secret(quote(self.password)) calls that the core Connection class already performs, covering both the direct-kwargs constructor and the from_uri path.

Closes: #38144

Test plan

• Added test_password_is_masked in task-sdk/tests/task_sdk/definitions/test_connection.py, covering both the kwargs constructor and from_uri.
• Verified against a pre-fix checkout that the new assertions fail without the change (masking returns False) and pass with it.
• ruff check and ruff format --check pass on the changed files.

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