chore(with-docker/Dockerfile): Some improvements (#11010)
### Description
I (think I) improved the Dockerfile of the web in the example
"with-docker".
1. The "base" image install `libc6-compat` once only
2. The "base" image set the workspace to `/app` once only
3. The "builder" image, which was doing the `prune` is renamed to
"initiator" because, you know, **it doesn't build the app...**
4. The "installer" image, which was doing the `build` is renamed to
"builder" because, you know, **it builds the app...**
5. A deprecated comment (I think) has been removed. But correct me, I am
probably wrong
### Testing Instructions
```
docker build -f apps/web/Dockerfile -t "awesome" .
```
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Co-authored-by: Anthony Shew <anthonyshew@gmail.com>
