fix(plugin): Ensure plugins are only installed if not deactivated (#8893) (#8901)

Co-authored-by: Oliver <oliver.henry.walters@gmail.com>
(cherry picked from commit fbe2131fa5)

Co-authored-by: Matthias Mair <code@mjmair.com>

src/backend/InvenTree/plugin/registry.py

@@ -290,7 +290,7 @@ class PluginsRegistry:
                 collect,
             )
 
-            if collect:
+            if collect and not settings.PLUGINS_INSTALL_DISABLED:
                 logger.info('Collecting plugins')
                 self.install_plugin_file()
                 self.plugin_modules = self.collect_plugins()