Make code pass the gitlab pipeline

Heyy @batigolix
Does this issue still needs work or is it already done?

Yes this issue still needs work.
No work has been done on this yet.

See the pipeline warnings:
https://git.drupalcode.org/project/dynamic_layouts/-/pipelines

daniel.j → made their first commit to this issue’s fork.

MR openned and fixes included for:
- phpstan
- phpcs
- stylelint
- eslint
- cspell

There are some fixes still required for eslint mostly related to module imports and loops (https://git.drupalcode.org/issue/dynamic_layouts-3458110/-/jobs/3210629).

Left few comments on the MR!12. Please do check once.