Fix Pydantic warnings - Githubissues

This PR fixes a few Pydantic deprecation warnings:

Closes #3507

[x] All the commits in this PR are properly PGP-signed and verified.
[x] This PR only contains functionality relevant to the issue.
[x] I have written unit tests for the changes or fixes I made.
[ ] I have checked the documentation and made changes where necessary.
[x] I have performed a self-review of my code and refactored it to the best of my abilities.

[ ] Tickets have been created for newly discovered issues.
[ ] For any non-trivial functionality, I have added integration and/or end-to-end tests.
[ ] I have informed others of any required .env changes files if required and changed the .env-dist accordingly.
[ ] I have included comments in the code to elaborate on what is not self-evident from the code itself, including references to issues and discussions online, or implicit behavior of an interface.

Checklist for code reviewers:

Copy-paste the checklist from the docs/source/templates folder into your comment.

Copy-paste the checklist from the docs/source/templates folder into your comment.

[x] I have checked out this branch, and successfully ran a fresh make reset.
[x] I confirmed that there are no unintended functional regressions in this branch:
- [x] I have managed to pass the onboarding flow
- [x] Objects and Findings are created properly
- [x] Tasks are created and completed properly
[x] I confirmed that the PR's advertised feature or hotfix works as intended.
[x] I checked the logs for errors and/or warnings and made issues where necessary

Looks good from what I can see. Tasks are created and run as expected. Findings are created.

I observed some weird behaviour around the JSON schema in boefje variants. I created a new ticket, as this is outside of the scope for this PR: #3569.
There appears to go something wrong with the parsing of some normalizer data, from webpage analysis. I created a new ticket for this: #3570

n/a