Update django-bootstrap3 requirement from ==23.1.* to ==23.6 (#3894)

* Update django-bootstrap3 requirement from ==23.1.* to ==23.6

 Removing our previous workarounds

* Fix import

src/pretix/control/forms/renderers.py

@@ -19,6 +19,7 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
+from bootstrap3.renderers import FieldRenderer, InlineFieldRenderer
 from bootstrap3.text import text_value
 from django.forms import CheckboxInput, CheckboxSelectMultiple, RadioSelect
 from django.forms.utils import flatatt
@@ -27,8 +28,6 @@ from django.utils.safestring import mark_safe
 from django.utils.translation import pgettext
 from i18nfield.forms import I18nFormField
 
-from pretix.base.forms.renderers import FieldRenderer, InlineFieldRenderer
-
 
 def render_label(content, label_for=None, label_class=None, label_title='', label_id='', optional=False):
     """