Update runtime 24.08 & disable screenshot feature

[pugaizai]

考虑到截图功能已经不被支持，使用 gnome runtime 已经没有必要，可以 revert #19
cc @chenzhiwei @zhuwjin

[flathubbot]

Started test build 165513

[flathubbot]

Build 165513 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/148594/com.qq.QQ.flatpakref

[flathubbot]

Started test build 165516

[flathubbot]

Started test build 165518

[flathubbot]

Build 165516 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/148597/com.qq.QQ.flatpakref

[flathubbot]

Build 165518 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/148599/com.qq.QQ.flatpakref

[flathubbot]

Started test build 165539

[flathubbot]

Build 165539 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/148620/com.qq.QQ.flatpakref