This PR looks pretty good. There is just no test yet that selects multiple technologies in the Slim select. You should write one of those.

Something does not work here. It seems to only save one in the multi-drop-down and nothing more than that. Look into why that happens and fix it.

Seems good to me.

First a few pieces of functionality feedback before I look at the code in too much detail:

• Why are the skills in the dropdown not sorted alphabetically? Make them sorted
• When navigating via the up and down arrow the already selected skills are not highlighted when navigating over them. This is especially bad if you select the first 5 skills and then want to navigate to the sixth one. I would argue we should just remove skills from the dropdown that are already selected. Being able to remove the via backspace or clicking on the little cross is good enough.
• After searching for a skill and then pressing enter the search input should be cleared.
• The dropdown has some horribly confusing boundary behaviour. E.g. Open the dropdown via arrow keys, select the third last skill and then the second last skill, press down and enter to deselect and then sometimes the down key goes up and silly stuff like that.
• When selecting a skill via enter you can then still continue searching for other skills. When you select one with the mouse button the search field loses focus and you have to manually press into it again.
• Don't force the user to remove the free text field via validation. We should still allow the user to make changes to projects without being forced to migrate to the new skills.