[13.x] Fix incorrect type hint in EncodedHtmlString::convert() docblock

[rpsohag]

Summary

Fixed a type mismatch in the EncodedHtmlString::convert() method's docblock.

Problem

The docblock annotated $withQuote as int but the actual parameter is bool $withQuote = true.

Solution

Changed the docblock annotation from @param int $withQuote to @param bool $withQuote.

Impact

• No behavior changes
• Documentation now matches implementation
• Improves static analysis accuracy