build(deps-dev): bump webpack-merge from 5.5.0 to 5.7.3 in /html (#567)

Bumps [webpack-merge](https://github.com/survivejs/webpack-merge) from 5.5.0 to 5.7.3.
- [Release notes](https://github.com/survivejs/webpack-merge/releases)
- [Changelog](https://github.com/survivejs/webpack-merge/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/survivejs/webpack-merge/compare/v5.5.0...v5.7.3)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

html/package.json

@@ -58,7 +58,7 @@
     "webpack": "4.44.2",
     "webpack-cli": "^4.3.0",
     "webpack-dev-server": "^3.11.0",
-    "webpack-merge": "^5.5.0"
+    "webpack-merge": "^5.7.3"
   },
   "dependencies": {
     "backoff": "^2.5.0",