add stable branch to extension version

[karman011]

extensions need this to keep post-upgrade usability

[flathubbot]

Started test build 152322

[flathubbot]

Build 152322 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/135407/com.visualstudio.code.flatpakref

[karman011]

please have a look @bilelmoussaoui

[flathubbot]

Started test build 154664

[flathubbot]

Build 154664 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/137752/com.visualstudio.code.flatpakref

[flathubbot]

Started test build 162452

[flathubbot]

Build 162452 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/145527/com.visualstudio.code.flatpakref

[flathubbot]

Started test build 164662

[flathubbot]

Build 164662 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/147738/com.visualstudio.code.flatpakref

[flathubbot]

Started test build 176584

[flathubbot]

Build 176584 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/159737/com.visualstudio.code.flatpakref

[flathubbot]

Started test build 189616

[flathubbot]

Build 189616 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/172896/com.visualstudio.code.flatpakref