Dependabot tries to bump PHP 8.5.8 to 8.6.0alpha2-fpm-bookworm

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Package ecosystem

Docker

### Package manager version

_No response_

### Language version

8.3

### Manifest location and content before the Dependabot update

8.2.6

### dependabot.yml content

```yaml
version: 2
updates:
- package-ecosystem: docker
directory: "/etc/php-fpm"
rebase-strategy: disabled
ignore:
- dependency-name: php
versions: [">= 8.3.0"]
```

### Updated dependency

_No response_

### What you expected to see, versus what you actually saw

8.2.7 (because we're on 8.2.6 and 8.2.7 is newly released)

8.3.0 we have excluded, but somehow that doesn't work for alpha releases?

### Native package manager behavior

_No response_

### Images of the diff or a link to the PR, issue, or logs

_No response_

### Smallest manifest that reproduces the issue

_No response_

Start with the dependabot.yml configuration and the Docker manifest under /etc/php-fpm, then reproduce the update using the PHP 8.2.6 version and the >= 8.3.0 ignore rule. Compare the candidate versions, including 8.2.7 and 8.6.0alpha2-fpm-bookworm. Done means the excluded alpha release is not selected while the eligible 8.2.7 update remains available.

Written by the indexing model from the issue text.