### Steps to reproduce

1. Login as an admin

2. Create project for which you activate the PIR ( under Project Settings > Project Initation Request) and remember the project attribute you selected as `Assignee when submitted`

3. Go to Project Settings > Project Attributes and disable the project attribute you selected for the PIR Assignee

4. Start a PIR using the above project as template


### What is the buggy behaviour?

* User cannot submit PIR

* Generic 500 is shown


### What is the expected behaviour?

1. Begin of the deletion TBD, maybeEnd of the deletion forbid users from disabling the project attribute if it's used in the Begin of the insertionPIR

1. Since there are now many cases in which the toggle for project attribute is disabled, show a hover card on disabled toggle switches. The card should contain explanations as of why this component is disabled.


End of the insertion Begin of the deletion PIR?


End of the deletion ###

### Screenshots and other files

PIR config

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/918088/content"> Begin of the insertion

End of the insertion Begin of the deletion

End of the deletion Project attributes config
<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/918087/content">
PIR error

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/918086/content">

### Environment information

**OpenProject version**

Core build

[d15c89249811e2e419179397abc795701595453c](https://github.com/opf/openproject/commits/d15c89249811e2e419179397abc795701595453c)

Product version

[8bcf61994d562039fe19c317ebac86a950d04744](https://github.com/opf/saas-openproject/commits/8bcf61994d562039fe19c317ebac86a950d04744)

Core version

OpenProject 17.1.0

**Browser**

* [ ] Chrome
* [x] Firefox
* [ ] Safari
* [ ] Mobile Safari
* [ ] Other (please specify)

**Operating System**

* [x] Windows
* [ ] Mac OS X
* [ ] Mobile iOS
* [ ] Mobile Android
* [ ] Linux (please specify distro)
* [ ] Chrome OS
* [ ] Other (please specify)