Bump mobx from 6.3.7 to 6.5.0 (#5038)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Sebastian Malton <sebastian@malton.name>

package.json

@@ -232,7 +232,7 @@
     "mac-ca": "^1.0.6",
     "marked": "^4.0.12",
     "md5-file": "^5.0.0",
-    "mobx": "^6.3.7",
+    "mobx": "^6.5.0",
     "mobx-observable-history": "^2.0.3",
     "mobx-react": "^7.3.0",
     "mobx-utils": "^6.0.4",