Update `webpack-dev-server`

[teo-lohrer-su]

Description

webpack-dev-server has an outdated dependency to http-proxy-middleware, which triggers a security alert from dependabot.

See: https://github.com/experimaestro/experimaestro-python/security/dependabot/95

However, 'webpack-dev-server` is already at the latest version available.

We should consider removing it, or update it when a new version is published.