fix: upgrade mithril from 2.0.4 to 2.2.0

Snyk has created this PR to upgrade mithril from 2.0.4 to 2.2.0.

See this package in npm:
https://www.npmjs.com/package/mithril

See this project in Snyk:
https://app.snyk.io/org/ytetsuro/project/5c9d5982-3265-4dba-90fc-6fc790ca8257?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -19,7 +19,7 @@
     "esbuild": "^0.14.39",
     "inversify": "^5.1.1",
     "jest": "^27.5.1",
-    "mithril": "^2.0.4",
+    "mithril": "^2.2.0",
     "pako": "^1.0.11",
     "php-parser": "^3.0.3",
     "postcss": "^8.4.13",