fix: move AppImage builds to coverage

- move AppImage builds to coverage in order to access them in release
  job
- expectedly better than `depends` as starting earlier

Signed-off-by: TheOneWithTheBraid <the-one@with-the-braid.cf>

.gitlab-ci.yml

@@ -195,7 +195,7 @@ build_linux_arm64:
       - build/linux/arm64/release/bundle/
 
 build_linux_appimage_x86:
-  stage: deploy
+  stage: coverage
   image: appimagecrafters/appimage-builder
   needs: [build_linux_x86]
   only:
@@ -215,7 +215,7 @@ build_linux_appimage_x86:
       - appimage/FluffyChat-x86_64.AppImage.zsync
 
 build_linux_appimage_arm64:
-  stage: deploy
+  stage: coverage
   image: appimagecrafters/appimage-builder
   needs: [build_linux_arm64]
   tags: [docker_arm64]