Fix exception when creating aiosqlite connections on aiosqlite==0.22.0

[donlon]

Description

After recent changes in aiosqlite 0.22.0 (omnilib/aiosqlite@1cd60ad), calling self._connection.start() results in 'Connection' object has no attribute 'start' exception. Creating connection in this way seems to be a misuse of its API. To fix it, we create connection with await aiosqlite.connect(...) instead of directly calling the internal methods.

Closes #2037

  File "/home/donlon/test.py", line 74, in init_db
    await Tortoise.generate_schemas()
  File "/home/donlon/works/.venv/lib/python3.14/site-packages/tortoise/__init__.py", line 594, in generate_schemas
    await generate_schema_for_client(connection, safe)
  File "/home/donlon/works/.venv/lib/python3.14/site-packages/tortoise/utils.py", line 46, in generate_schema_for_client
    await generator.generate_from_string(schema)
  File "/home/donlon/works/.venv/lib/python3.14/site-packages/tortoise/backends/base/schema_generator.py", line 504, in generate_from_
string
    await self.client.execute_script(creation_string)
  File "/home/donlon/works/.venv/lib/python3.14/site-packages/tortoise/backends/sqlite/client.py", line 43, in translate_exceptions_
    return await func(self, query, *args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/donlon/works/.venv/lib/python3.14/site-packages/tortoise/backends/sqlite/client.py", line 167, in execute_script
    async with self.acquire_connection() as connection:
               ~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/home/donlon/works/.venv/lib/python3.14/site-packages/tortoise/backends/base/client.py", line 266, in __aenter__
    await self.ensure_connection()
  File "/home/donlon/works/.venv/lib/python3.14/site-packages/tortoise/backends/base/client.py", line 261, in ensure_connection
    await self.client.create_connection(with_db=True)
  File "/home/donlon/works/.venv/lib/python3.14/site-packages/tortoise/backends/sqlite/client.py", line 82, in create_connection
    self._connection.start()
    ^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'Connection' object has no attribute 'start'

How Has This Been Tested?

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added the changelog accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[codspeed-hq]

CodSpeed Performance Report

Merging #2035 will not alter performance

_{Comparing donlon:develop (7570e09) with develop (dd9f9c5)}

Summary

✅ 16 untouched

[coveralls]

Pull Request Test Coverage Report for Build 20197313985

Details

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.001%) to 90.728%

---

Totals
Change from base Build 20169305593:	-0.001%
Covered Lines:	6631
Relevant Lines:	7194

---

💛 - Coveralls