chore(deps): bump chart.js from 2.9.3 to 2.9.4 in /webpack

Bumps [chart.js](https://github.com/chartjs/Chart.js) from 2.9.3 to 2.9.4.
- [Release notes](https://github.com/chartjs/Chart.js/releases)
- [Commits](chartjs/Chart.js@v2.9.3...v2.9.4)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

webpack/package.json

@@ -15,7 +15,7 @@
     "autoprefixer": "^9.8.6",
     "babel-eslint": "^10.1.0",
     "babel-loader": "^8.1.0",
-    "chart.js": "^2.9.3",
+    "chart.js": "^2.9.4",
     "clipboard": "^2.0.6",
     "css-loader": "^4.2.2",
     "cssnano": "^4.0.1",