fix: Autofocus does not work reliable for TextFields in dialogs

[martinbu]

🐛 Bug Report

Autofocus does not work reliable for TextFields in dialogs. This was not an issue before version v4.9.0.
By not reliable I mean, that it sometimes works, but not all the time. On the demo page it works sometimes, on my own application it never works.

For me the issue is resolved if I remove the tabindex="-1" from the fluent-dialog in FluentDialog.razor added by this commit

💻 Repro or Code Sample

Just add Autofucus="true" to one of the text fields in SimpleDialog.razor in the dialog examples.

[vnbaaij]

Will be corrected with PR in next release (v4.9.4.). Closing this one