**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
log = ""
        if os.path.exists(location):
            try:
                with open(location) as file:
                    log += f"*** Reading local file: {location}\n"
                    log += "".join(file.readlines())
            except Exception as e:
                log = f"*** Failed to load local log file: {location}\n"
                log += f"*** {str(e)}\n"
        elif conf.get('core', 'executor') == 'KubernetesExecutor':
            try:
                from airflow.kubernetes.kube_client import get_kube_client
                kube_client = get_kube_client()
                if len(ti.hostname) >= 63:
                    
                    
                    
                    pod_list = kube_client.list_namespaced_pod(conf.get('kubernetes', 'namespace'))
                    matches = [
                        pod.metadata.name
                        for pod in pod_list.items
                        if pod.metadata.name.startswith(ti.hostname)
                    ]
                    if len(matches) == 1:
                        if len(matches[0]) > len(ti.hostname):
                            ti.hostname = matches[0]
                log += '*** Trying to get logs (last 100 lines) from worker pod {} ***\n\n'.format(
                    ti.hostname
                )
                res = kube_client.read_namespaced_pod_log(