Mark GNOME 3.32 as supported, all others as unsupported

The class syntax is unsupported in pre-ES6 versions, and
using ExtensionUtils instead of convenience.js is only possible
in 3.32.

data/metadata.json

@@ -10,17 +10,7 @@
     "gettext-domain": "hamster-shell-extension",
     "settings-schema": "org.gnome.shell.extensions.project-hamster",
     "shell-version": [
-        "3.10",
-        "3.12",
-        "3.14",
-        "3.16",
-        "3.18",
-        "3.20",
-        "3.22",
-        "3.24",
-        "3.26",
-        "3.28",
-        "3.30"
+        "3.32"
     ],
     "url": "https://github.com/projecthamster/hamster-shell-extension.git",
     "uuid": "contact@projecthamster.org",