Wrong `webpack` version causes `selenium-tests` to fail locally

[pichlermarc]

What happened?

Selenium tests are currently not working. This is seemingly due to the config being written for webpack v5+

Steps to Reproduce

• cd ./selenium-tests
• npm install
• npm run server <- this will fail

Expected Result

Server starting up so that tests can be run with npm run all:local

Actual Result

Server startup fails with:

> @opentelemetry/selenium-tests@1.7.0 server
> webpack serve --progress --port 8090 --config webpack.dev.js --hot --host 0.0.0.0

[webpack-cli] Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration.target should be one of these:
   "web" | "webworker" | "node" | "async-node" | "node-webkit" | "electron-main" | "electron-renderer" | "electron-preload" | function
   -> Environment to build for
   Details:
    * configuration.target should be one of these:
      "web" | "webworker" | "node" | "async-node" | "node-webkit" | "electron-main" | "electron-renderer" | "electron-preload"
    * configuration.target should be an instance of function

Additional Details

Can be fixed by using the following webpack versions:

    "webpack": "^5.60.0",
    "webpack-cli": "^4.10.0",
    "webpack-dev-server": "^4.5.0",
    "webpack-merge": "^5.8.0"

OpenTelemetry Setup Code

n/a

package.json

n/a

Relevant log output

see "Actual Result"

[SaumyaBhushan]

@pichlermarc Can you please review the changes ?