Optional enum "Choose here" as empty value throws error
### Node Version

20

### NPM/Yarn/PNPM Version

NPM 10.9.0

### Strapi Version

5.10.3

### Operating System

MacOS

### Database

SQLite

### Javascript or Typescript

Typescript

### Reproduction URL

https://github.com/ellawir/strapi-latest-test

### Bug Description

Optional enumeration fields throw validation error when selecting the "Choose here" value. Similar bugs have previously been mentioned [here](https://github.com/strapi/strapi/pull/22141) and the "Choose here" option seems to have been added back to optional fields on v5 with [this](https://github.com/strapi/strapi/pull/22139) PR, but as the provided minimal reproducible example shows, selecting "Choose here" throws an error in later versions. It seems unnecessary that we'd have to add an option for empty values on optional enums. 

### Steps to Reproduce


1. Create a content type with an optional enum ("Test" collection type in provided reproduction repository)
2. Create new entry in content manager, select enum = option1 and successfully save

![Image](https://github.com/user-attachments/assets/a34144c6-e936-4400-becb-84dc22b488f5)

3. Select enum = "Choose here" and get error “enum must be one of the following values: option1, option2”

![Image](https://github.com/user-attachments/assets/f5a62368-93bd-45d7-9128-eadc210e4e89)

### Expected Behavior

As discussed in related bug and PR, "Choose here" should be selectable as empty value on optional enum field, as it was in Strapi 4.

### Logs

```shell

```

### Code Snippets

_No response_

### Media

_No response_

### Additional information

_No response_

### Confirmation Checklist

- [x] I have checked the existing [issues](https://github.com/strapi/strapi/issues) for duplicates.
- [x] I agree to follow this project's [Code of Conduct](https://github.com/strapi/strapi/blob/develop/CODE_OF_CONDUCT.md).