title: Python not decoding JSON because "encoding" is an unexpected argument
body: <p>I have a Django 2.2.23 app, running on Python 3.9.4. I have django-extensions 2.2.9.</p>
  <p>I have a model that has a <code>django_extensions.db.fields.json.JSONField</code> attribute (which, AFAIK, is just a text field auto-serialized). I mention this because when the JSON is deserialized, the django-extensions library does it like this:</p>
  <pre class="lang-py prettyprint-override"><code>def loads(txt):
      value = json.loads(
          txt,
          encoding=settings.DEFAULT_CHARSET
      )
      return value
  </code></pre>
  <p>The problem is that the library imported by <code>import json</code> gives me an error when it's called this way:</p>
  <pre><code>Python 3.9.4 (default, Apr  5 2021, 01:50:46)
  [Clang 12.0.0 (clang-1200.0.32.29)] on darwin
  Type &quot;help&quot;, &quot;copyright&quot;, &quot;credits&quot; or &quot;license&quot; for more information.
  &gt;&gt;&gt; import json
  &gt;&gt;&gt; json.loads(&quot;{}&quot;, encoding=&quot;UTF-8&quot;)
  Traceback (most recent call last):
    File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
    File &quot;/usr/local/Cellar/python@3.9/3.9.4/Frameworks/Python.framework/Versions/3.9/lib/python3.9/json/__init__.py&quot;, line 359, in loads
      return cls(**kw).decode(s)
  TypeError: __init__() got an unexpected keyword argument 'encoding'
  &gt;&gt;&gt;
  </code></pre>
  <p>The end result is that I am unable to load any of the records that contain a <code>JSONField</code> from the database because the JSONDecoder can't handle being passed an <code>encoding</code> argument.</p>
  <p>I was under the impression that Python's json library was simplejson. But looking at the source for that, it does handle <code>encoding</code>. But if I look at the json library in &quot;/usr/local/Cellar/python@3.9/3.9.4/Frameworks/Python.framework/Versions/3.9/lib/python3.9/json/<strong>init</strong>.py&quot; (as specified in the error above), this decoder definitely does not.</p>
  <p>This is clearly incorrect behavior, but I don't know what I need to upgrade in order to get the right thing to happen.</p>