[Django 4.2]: Fix: object has no attribute 'is_ajax'

[irtazaakram]

Description

Fixes issue when upgrading to Django 4.2

/usr/lib/python3.8/unittest/mock.py:637: AttributeError
___________ TestCommonExceptions400.test_alreadyrunningerror_2_False ___________

self = <lms.djangoapps.instructor.tests.test_api.TestCommonExceptions400 testMethod=test_alreadyrunningerror_2_False>
is_ajax = False

    @ddt.data(True, False)
    def test_alreadyrunningerror(self, is_ajax):
>       self.request.is_ajax.return_value = is_ajax

lms/djangoapps/instructor/tests/test_api.py:279: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <Mock spec='HttpRequest' id='140253030049632'>, name = 'is_ajax'

    def __getattr__(self, name):
        if name in {'_mock_methods', '_mock_unsafe'}:
            raise AttributeError(name)
        elif self._mock_methods is not None:
            if name not in self._mock_methods or name in _all_magics:
>               raise AttributeError("Mock object has no attribute %r" % name)
E               AttributeError: Mock object has no attribute 'is_ajax'

Django docs
https://docs.djangoproject.com/en/3.1/releases/3.1/#id2

The HttpRequest.is_ajax() method is deprecated as it relied on a jQuery-specific way of signifying AJAX calls, while current usage tends to use the JavaScript Fetch API. Depending on your use case, you can either write your own AJAX detection method, or use the new HttpRequest.accepts() method if your code depends on the client Accept HTTP header.

Reference
#33055

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX staging environment in preparation for a release to production.