[WIP] Upgrade flask-appbuilder to ~=2.3

[feluelle]

Upgrade flask-appbuilder to ~=2.3

• update requirements.txt

The new version 2.3.0 allows a wider version range of the marshmallow dependency.

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Issue link: WILL BE INSERTED BY boring-cyborg

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• Description above provides context of the change
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[kaxil]

@feluelle Can you resolve conflicts please

[feluelle]

@kaxil closing this due to #8602 :)