Bug: Mentions Format was not applied, the Font size style was not applied in html

Lexical version:

## Steps To Reproduce

1. Add some text
2. Then add any one mention.
3. After the mention add some text(not necessary)
4. Increase the font style using the FontDropDown in term of px
5. In Tree View on export DOM you can able to notice that font size was not applied for the required mentions

**Sample Images**

Link to code example:

## The current behavior

## The expected behavior
The Font size should also applicable for the Mentions.
## Impact of fix

Start by reproducing the issue with text, a mention, and the FontDropDown in the Tree View, then inspect the HTML export path for how font size is applied to mentions. Done means the exported HTML preserves the selected font size on the affected mentions.

Written by the indexing model from the issue text.