MySQL 8 fails to run GIS tests

[Tom Forbes]

When attempting to run the GIS test suite using the mysql:8 docker image I get the following error:

    Creating table relatedapp_author
    Creating table relatedapp_article
    Creating table relatedapp_book
    Creating table relatedapp_event
    Running deferred SQL…
Traceback (most recent call last):
  File "/tests/django/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "/tests/django/django/db/backends/mysql/base.py", line 71, in execute
    return self.cursor.execute(query, args)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 250, in execute
    self.errorhandler(self, exc, value)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/connections.py", line 50, in defaulterrorhandler
    raise errorvalue
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 247, in execute
    res = self._query(query)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 412, in _query
    rowcount = self._do_query(q)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 375, in _do_query
    db.query(q)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/connections.py", line 276, in query
    _mysql.connection.query(self, query)
_mysql_exceptions.OperationalError: (1070, 'Too many key parts specified; max 1 parts allowed')

[Florian Apolloner]

In 4269648c0fe59a7edfa11f022f17cd251e9c49ca:

Fixed #29876 -- MySQL does not support SPATIAL fields in unique indices.