Update dependency filesize to v6.4.0

Author: renovate[bot]

package-lock.json

@@ -209,7 +209,7 @@
     "electron-log": "4.4.8",
     "electron-updater": "^5.0.1",
     "ffi-napi": "^4.0.3",
-    "filesize": "6.1.0",
+    "filesize": "6.4.0",
     "lazy-brush": "^1.0.1",
     "react": "16.13.0",
     "react-dom": "16.13.0",