Remove webpack and karma and related code

build/build.js

build/dev-client.js

build/dev-server.js

build/utils.js

build/webpack.base.conf.js

build/webpack.dev.conf.js

build/webpack.prod.conf.js

config/dev.env.js

config/index.js

config/prod.env.js

config/test.env.js

eslint.config.mjs

package.json

test/unit/.eslintrc

test/unit/index.js

test/unit/karma.conf.js

yarn.lock