Add typing_extensions to flatpak requirement

[SqAtx]

Without it, the weekly flatpak fails on startup:

Traceback (most recent call last):
  File "/app/bin/gtg", line 98, in <module>
    from GTG.gtk.application import Application
  File "/app/lib/python3.11/site-packages/GTG/gtk/application.py", line 30, in <module>
    from GTG.core.datastore import Datastore
  File "/app/lib/python3.11/site-packages/GTG/core/datastore.py", line 30, in <module>
    from GTG.core.tasks import TaskStore, Filter
  File "/app/lib/python3.11/site-packages/GTG/core/tasks.py", line 35, in <module>
    from GTG.core.base_store import BaseStore, StoreItem
  File "/app/lib/python3.11/site-packages/GTG/core/base_store.py", line 29, in <module>
    from typing_extensions import Self
ModuleNotFoundError: No module named 'typing_extensions'

The requirement has been necessary since 908da7d

[SqAtx]

Note that I haven't been able to test this yet

[gycsaba96]

Note that I haven't been able to test this yet

I am not yet that familiar with the flatpak build pipeline. However, it seems the python3-requirements.yaml file should also be updated based on this comment. Another option could be to leverage typing.TYPE_CHECKING and treat typing_extensions as an optional dependency not included in the flatpak build.

(If I understand correctly, this will be a quick fix before PR 1163 is merged.)

[SqAtx]

You might be right - I tried to build it and it still didn't work. I'll try and follow your suggestion tomorrow and update this if it works.

[SqAtx]

Hm I haven't been able to make that command work.

I created #1179 to document the fact that the weekly flatpak isn't running, and will make another attempt at fixing it when I have time.

[gycsaba96]

Hm I haven't been able to make that command work.

Maybe we are facing the same error: error: app/org.gnome.Sdk/x86_64/46 not installed
Installing the SDK solved the problem: flatpak install org.gnome.Sdk/x86_64/46

Again, using typing.TYPE_CHECKING seems also a viable solution that keeps the flatpak cleaner.

Or we can just wait until PR #1163 is merged. :)