docs-builder not respecting alt text

### Describe the bug

documented here: https://elastic.github.io/docs-builder/syntax/images/#inline-image-titles

> For inline images, the alt text always overrides any title specified in the Markdown. This ensures consistent accessibility where both the alt and title attributes contain the same descriptive text.
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in practice, the title always wins:

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### Expected behavior

alt text appears as alt text when specified, instead of the title

### Steps to reproduce

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\+ hover over image

### Tooling

- [x] docs-builder
- [ ] migration tooling
- [ ] I'm not sure