This commit is purely to integration test newer versions of the GitPod
workspace image and not supposed to be merged.

Changelog: changed

We currently force the static webpack compilation in GitPod. This
behaviour is annoying if someone changes frontend assets, because all of
GitLab needs to be recompiled, which is time consuming.

This enables the normal webpack dev server, but with live reload
disabled. enabling live reload is being tracked here:
https://gitlab.com/gitlab-org/gitlab-development-kit/-/issues/1444

Usually, developers run a single test locally.
Disabling eager loading by default in test environment should increase
productivity since it saves around 10 seconds:

With `eager_load` as `true`:
```bash
bogdanvlviv@lenovo:~/gitlab-development-kit/gitlab$ bin/rspec spec/models/users_statistics_spec.rb
Run options: include {:focus=>true}

All examples were filtered out; ignoring {:focus=>true}

Test environment set up in 5.122837013 seconds
......

Finished in 8.51 seconds (files took 16.46 seconds to load)
6 examples, 0 failures
```

With `eager_load` as `false`:
```bash
bogdanvlviv@lenovo:~/gitlab-development-kit/gitlab$ bin/rspec spec/models/users_statistics_spec.rb
Run options: include {:focus=>true}

All examples were filtered out; ignoring {:focus=>true}

Test environment set up in 5.013345478 seconds
......

Finished in 8.24 seconds (files took 7.18 seconds to load)
6 examples, 0 failures
```

Inspired by https://github.com/rails/rails/pull/43508...

By setting the environment variable `GITLAB_TEST_EAGER_LOAD=false`
disable Rails' eager loading of class in the `test` environment
which improves the load time of specs.

Signed-off-by: Rémy Coutable <remy@rymai.me>

This reverts merge request !47293

This reverts commit ca3fec83f16217354f4f3f4c81e3722904774b0c