[5.1.x] Fixed ambiguous pronoun reference in docs/ref/models/fields.txt.

Backport of 9cc3970 from main.

Author: cliff688

docs/ref/models/fields.txt

@@ -505,7 +505,7 @@ The default value can also be set at the database level with
 .. attribute:: Field.editable
 
 If ``False``, the field will not be displayed in the admin or any other
-:class:`~django.forms.ModelForm`. They are also skipped during :ref:`model
+:class:`~django.forms.ModelForm`. It will also be skipped during :ref:`model
 validation <validating-objects>`. Default is ``True``.
 
 ``error_messages``