normalize-links.sh takes a long time to complete

When we do build the single Docker images, the post-processing after the site is built, takes an awfully long time. The minimum is 20 minutes.

The offending piece is the normalize-links.sh and all the sed commands it runs.

Because of this, we run into issues and jobs keep failing, probably due to high memory or I/O usage:

ERROR: failed to solve: DeadlineExceeded: no active session for yi3fc4449n5mmbn4vzle7svib: context deadline exceeded

We need to find a way to refactor this.

Related issues

• Previous refactoring !3701 (merged)