Swapped out Packery for MagicGrid

This switches the Gallery shortcode to use MagicGrid instead of Packery.
The main benefit is size (2.7k as opposed to 32k), and the results are
mostly similar minus a few differences in image position.

package.json

@@ -39,7 +39,7 @@
     "fuse.js": "^7.0.0",
     "jquery": "^3.7.1",
     "katex": "^0.16.9",
-    "packery": "^2.1.2",
+    "magic-grid": "^3.2.4",
     "prettier": "^3.2.5",
     "prettier-plugin-go-template": "^0.0.15",
     "prettier-plugin-tailwindcss": "^0.5.11",
@@ -85,8 +85,8 @@
       "to": "assets/lib/jquery/jquery.slim.min.js"
     },
     {
-      "from": "node_modules/packery/dist/packery.pkgd.min.js",
-      "to": "assets/lib/packery/packery.pkgd.min.js"
+      "from": "node_modules/magic-grid/dist/magic-grid.min.js",
+      "to": "assets/lib/magic-grid/magic-grid.min.js"
     },
     {
       "from": "node_modules/tw-elements/js/tw-elements.umd.min.js",