**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 try_number is None:
            next_try = task_instance.next_try_number
            try_numbers = list(range(1, next_try))
        elif try_number < 1:
            logs = [
                [('default_host', f'Error fetching the logs. Try number {try_number} is invalid.')],
            ]
            return logs, [{'end_of_log': True}]
        else:
            try_numbers = [try_number]
        logs = [''] * len(try_numbers)
        metadata_array = [{}] * len(try_numbers)
        for i, try_number_element in enumerate(try_numbers):
            log, metadata = self._read(task_instance, try_number_element, metadata)
            
            
            logs[i] = log if self._read_grouped_logs() else [(task_instance.hostname, log)]
            metadata_array[i] = metadata
        return logs, metadata_array
    def _init_file(self, ti):
        """
        Create log directory and give it correct permissions.
        :param ti: task instance object
        :return: relative log path of the given task instance
        """