Update base- and runtime-version to 23.08

[horas13]

• update runtime-version in chat.delta.core.rust.yml
• update base- and runtime-version in chat.delta.desktop.yml

[flathubbot]

Started test build 70779

[flathubbot]

Build 70779 failed

[flathubbot]

Started test build 70833

[flathubbot]

Build 70833 failed

[flathubbot]

Started test build 71256

[flathubbot]

Build 71256 failed

[flathubbot]

Started test build 72595

[flathubbot]

Build 72595 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/55248/chat.delta.desktop.flatpakref