feat: remove required fields from not required fields

[Sboonny]

• [x] I have read Chapter's contributing guidelines.
• [x] My pull request has a descriptive title (not a vague title like Update README.md).
• [x] My pull request targets the main branch of Chapter.

Event is now can be created without these fields, unless I missed something 🤔, so we can remove them

[ghost]

👇 Click on the image for a new way to code review

- Make big changes easier — review code in small groups of related files - Know where to start — see the whole change at a glance - Take a code tour — explore the change with an interactive tour - Make comments and review — all fully sync’ed with github [Try it now!](https://app.codesee.io/r/reviews?pr=2350&src=https%3A%2F%2Fgithub.com%2FfreeCodeCamp%2Fchapter)

Legend

[Sboonny]

Do we remove capacity, I haven't checked, but people should be able to join an event even with capacity of 1🤔.

Maybe the other way around, maybe use capacity to limit attendance 🤔

Let me check first about how we use capacity, then open issue for this 👍

[gikf]

They still can opt for attending when event is at full capacity, but they will be placed on the waitlist.