### Discussed in https://github.com/apache/airflow/discussions/19366

<div type='discussions-op-text'>

<sup>Originally posted by **a-pertsev** November  2, 2021</sup>
### Apache Airflow version

2.2.1 (latest released)

### Operating System

Ubuntu 20.04 LTS

### Versions of Apache Airflow Providers

apache-airflow-providers-amazon==2.3.0
apache-airflow-providers-apache-cassandra==2.1.0
apache-airflow-providers-ftp==2.0.1
apache-airflow-providers-google==6.0.0
apache-airflow-providers-http==2.0.1
apache-airflow-providers-imap==2.0.1
apache-airflow-providers-jdbc==2.0.1
apache-airflow-providers-mysql==2.1.1
apache-airflow-providers-postgres==2.3.0
apache-airflow-providers-presto==2.0.1
apache-airflow-providers-slack==4.1.0
apache-airflow-providers-sqlite==2.0.1

### Deployment

Virtualenv installation

### Deployment details

_No response_

### What happened

Got error when manually run newly created task in already finished dag run (in UI).

### What you expected to happen

"Run" button should work without exceptions.

### How to reproduce

1. Define a dag with some tasks.
2. Create dag run (manually or by schedule)
3. Add new task into dag, deploy code
4. Select new task in UI and press "Run" button

### Anything else

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
</div>
airflow/www/views.py
"""Formats hidden fields"""
        key = self.get('key')
        val = self.get('val')
        if secrets_masker.should_hide_value_for_key(key):
            return Markup('*' * 8)
        if val:
            return val
        else:
            return Markup('<span class="label label-danger">Invalid</span>')
    formatters_columns = {
        'val': hidden_field_formatter,
    }
    validators_columns = {'key': [validators.DataRequired()]}
    def prefill_form(self, form, request_id):
        if secrets_masker.should_hide_value_for_key(form.key.data):
            form.val.data = '*' * 8
    extra_args = {"can_create_variable": _can_create_variable}
    @action('muldelete', 'Delete', 'Are you sure you want to delete selected records?', single=False)
    def action_muldelete(self, items):
        """Multiple delete."""
        self.datamodel.delete_all(items)
        self.update_redirect()
        return redirect(self.get_redirect())
    @action('varexport', 'Export', '', single=False)
    def action_varexport(self, items):