**Description**

Make HttpSensor `headers` parameter templated.

**Use case / motivation**

This would allow for passing data from other tasks, such as an API token, in the headers.

**Related Issues**

N/A
airflow/providers/http/sensors/http.py
from airflow.utils.operator_helpers import make_kwargs_callable
        self.log.info('Poking: %s', self.endpoint)
        try:
            response = self.hook.run(
                self.endpoint,
                data=self.request_params,
                headers=self.headers,
                extra_options=self.extra_options,
            )
            if self.response_check:
                kwargs_callable = make_kwargs_callable(self.response_check)
                return kwargs_callable(response, **context)
        except AirflowException as exc:
            if str(exc).startswith("404"):
                return False
            raise exc
        return True