Add support for Gnome 45, drop support for Gnome < 44

Because of their switch to standard JavaScript modules (ESM) that break
support for older versions. See:
https://blogs.gnome.org/shell-dev/2023/09/02/extensions-in-gnome-45/
https://gjs.guide/extensions/upgrading/gnome-shell-45.html

README.md

@@ -82,6 +82,11 @@ In case it doesn't work, you may need to add your gnome version in
 gdbus call --session --dest org.gnome.Shell --object-path /org/gnome/Shell/Extensions/GnomeMagicWindow --method org.gnome.Shell.Extensions.GnomeMagicWindow.magic_key_pressed Terminator terminator
 ```
 
+## For Gnome versions < 45
+
+Use this repo on commit b640974 or before, and read the README file from that
+version.
+
 ## For Gnome versions < 41
 
 Use this repo on commit 26230da or before, and read the README file from that

extension.js

@@ -27,14 +27,16 @@ const BINDINGS = [
   // },
 ];
 
-const { Gio } = imports.gi;
-const Main = imports.ui.main;
-const Mainloop = imports.mainloop;
-const Meta = imports.gi.Meta;
-const Shell = imports.gi.Shell;
-const Util = imports.misc.util;
-
-class Extension {
+import Gio from 'gi://Gio';
+import { Extension } from 'resource:///org/gnome/shell/extensions/extension.js';
+import * as Main from 'resource:///org/gnome/shell/ui/main.js';
+const Mainloop = imports.mainloop
+import Meta from 'gi://Meta'; // const Meta = imports.gi.Meta; //TODO
+import Shell from 'gi://Shell';
+import * as Util from 'resource:///org/gnome/shell/misc/util.js';
+
+
+export default class GnomeMagicWindowExtension extends Extension {
   enable() {
     this._dbus = Gio.DBusExportedObject.wrapJSObject(`
       <node>
@@ -129,7 +131,3 @@ class Extension {
     }
   }
 }
-
-function init() {
-  return new Extension();
-}

metadata.json

@@ -3,5 +3,5 @@
   "description": "Bind a key to a specific program in Gnome Shell",
   "uuid": "gnome-magic-window@adrienverge",
   "url": "https://github.com/adrienverge/gnome-magic-window",
-  "shell-version": ["40", "41", "42", "43", "44"]
+  "shell-version": ["45"]
 }