[FTBFS] flask-appbuilder 4.1.4+ds-3build1 fails to build against python3-flask-sqlalchemy 3.0.3-1

[Benjamin Drung]

flask-appbuilder 4.1.4+ds-3build1 fails to build from source against python3-flask-sqlalchemy 3.0.3-1:

```
PYTHONPATH=. python3 -m sphinx -N -bhtml docs/ build/html
Running Sphinx v5.3.0

Configuration error:
There is a programmable error in your configuration file:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/sphinx/config.py", line 350, in eval_config_file
    exec(code, namespace)
  File "/<<PKGBUILDDIR>>/docs/conf.py", line 23, in <module>
    import flask_appbuilder
  File "/<<PKGBUILDDIR>>/flask_appbuilder/__init__.py", line 5, in <module>
    from .api import ModelRestApi # noqa: F401
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/<<PKGBUILDDIR>>/flask_appbuilder/api/__init__.py", line 23, in <module>
    from flask_appbuilder.models.sqla import Model
  File "/<<PKGBUILDDIR>>/flask_appbuilder/models/sqla/__init__.py", line 5, in <module>
    from flask_sqlalchemy import (
ImportError: cannot import name '_QueryProperty' from 'flask_sqlalchemy' (/usr/lib/python3/dist-packages/flask_sqlalchemy/__init__.py)
```

Upstream bug report: https://github.com/dpgaspar/Flask-AppBuilder/issues/2038

Updating to 4.3.1 (plus the ustream commits until 2023-05-16) to make it work with flask 2.2.2 is not enough to address the build failures.