**Apache Airflow version**:
2.1.0

**What happened**:
When printing emoji to a DAG log, the Airflow dashboard fails to display the entire log.
When checking the output log in the Airflow dashboard, the following error message appears:

> *** Failed to load local log file: /tmp/dag_name/task_name/2021-07-06T10:49:18.136953+00:00/1.log
> *** 'ascii' codec can't decode byte 0xf0 in position 3424: ordinal not in range(128)

**What you expected to happen**:
The log should be displayed.

<!-- What do you think went wrong? -->


**How to reproduce it**:
Insert the following into any Python DAG, then run it.
`print("💼")`

**How often does this problem occur?**
Every log with an emoji in it prints an error.

**Why would anyone even want to print emoji in their logs?**
When they're part of the dataset you're processing.
airflow/utils/log/file_task_handler.py
if self.handler:
            self.handler.emit(record)
    def flush(self):
        if self.handler:
            self.handler.flush()
    def close(self):
        if self.handler:
            self.handler.close()
    def _render_filename(self, ti, try_number):
        if self.filename_jinja_template:
            if hasattr(ti, 'task'):
                jinja_context = ti.get_template_context()
                jinja_context['try_number'] = try_number
            else:
                jinja_context = {
                    'ti': ti,
                    'ts': ti.execution_date.isoformat(),
                    'try_number': try_number,
                }
            return self.filename_jinja_template.render(**jinja_context)
        return self.filename_template.format(
            dag_id=ti.dag_id,
            task_id=ti.task_id,
            execution_date=ti.execution_date.isoformat(),
            try_number=try_number,
        )
    def _read_grouped_logs(self):