Added woff2 and mp4 file fingerprinting to Admin

refs https://ghost.slack.com/archives/C027S85FS/p1688984189646059?thread_ts=1688979558.123869&cid=C027S85FS

- this enables those file extensions to get fingerprinted so the
  filenames contain hashes

ghost/admin/ember-cli-build.js

@@ -145,6 +145,8 @@ module.exports = function (defaults) {
                 'map',
                 'svg',
                 'ttf',
+                'woff2',
+                'mp4',
                 'ico'
             ]
         },