Refs #30485 -- Removed non-representative test that emitted a warning.

Previously, when running the Django test suite with warnings enabled,
the following was emitted:

    /usr/lib64/python3.7/urllib/parse.py:915: BytesWarning: str() on a bytearray instance
      v = quote_via(str(v), safe, encoding, errors)

This occurred due to the bytearray() being passed to
urllib.parse.urlencode() which eventually calls str() on it. The test
does not represent desired real world behavior. Rather than test for and
assert strange unspecified behavior that emits a warning, remove it.

This was also discussed in PR #11374.

tests/utils_tests/test_http.py

@@ -74,7 +74,6 @@ class URLEncodeTests(SimpleTestCase):
 
     def test_dict_with_bytearray(self):
         self.assertEqual(urlencode({'a': bytearray(range(2))}, doseq=True), 'a=0&a=1')
-        self.assertEqual(urlencode({'a': bytearray(range(2))}, doseq=False), 'a=bytearray%28b%27%5Cx00%5Cx01%27%29')
 
     def test_generator(self):
         self.assertEqual(urlencode({'a': range(2)}, doseq=True), 'a=0&a=1')