chore(deps): Remove unnecessary submodules

.gitmodules

@@ -1,21 +1,12 @@
 [submodule "external/nextcloud-server"]
 	path = external/nextcloud-server
 	url = https://github.com/nextcloud/server.git
-[submodule "external/nextcloud-news"]
-	path = external/nextcloud-news
-	url = https://github.com/nextcloud/news.git
 [submodule "external/seti-ui"]
 	path = external/seti-ui
 	url = https://github.com/jesseweed/seti-ui.git
-[submodule "external/nextcloud-notes"]
-	path = external/nextcloud-notes
-	url = https://github.com/nextcloud/notes.git
 [submodule "external/nextcloud-notifications"]
 	path = external/nextcloud-notifications
 	url = https://github.com/nextcloud/notifications.git
-[submodule "external/nextcloud-uppush"]
-	path = external/nextcloud-uppush
-	url = https://github.com/UP-NextPush/server-app.git
 [submodule "external/flathub-shared-modules"]
 	path = external/flathub-shared-modules
 	url = https://github.com/flathub/shared-modules.git