`load_schema` race

[askalt]

These lines result in the exception, trying to connect to the instance that actively applies DDL due to the race between object creation:

tarantool-python/tarantool/connection.py

Lines 1409 to 1410 in 28310fc

	self.schema.fetch_space_all()
	self.schema.fetch_index_all()

As these two fetches are non-transactional, the second one can return an index for space that is not fetched at the first fetch, resulting in:

Traceback (most recent call last):
  File "/python/lib/python3.11/site-packages/tarantool/connection.py", line 1097, in connect
    self.load_schema()
  File "/python/lib/python3.11/site-packages/tarantool/connection.py", line 1316, in load_schema
    self.schema.fetch_index_all()
  File "/python/lib/python3.11/site-packages/tarantool/schema.py", line 377, in fetch_index_all
    SchemaIndex(row, self.schema[row[0]])