[MultiComboBox]: [Proper announcements are not provided for the screen readers in case of wrong input or invalid inputs]

Describe the bug

The screen reader reads an error as "No Tokens Value State Error Invalid entry No Tokens" or sometimes no announcements for the wrong input

https://github.com/user-attachments/assets/f116fb0f-4b9e-4500-817f-713820368220

Isolated Example

No response

Reproduction steps

1. Enter anything like "x" or "11" which does not exist
2. we get message on screen "invalid entry" which is dynamic we can change it but the annoucments are not there

Expected Behaviour

Error messages must be clear and descriptive enough for a screen reader user to understand what went wrong and how to fix it.

Screenshots or Videos

https://github.com/user-attachments/assets/fe9d3c5c-e225-48b8-9e0f-291b25dce9a6

UI5 Web Components for React Version

2.24.0

UI5 Web Components Version

2.24.0

Browser

Safari

Operating System

MacOs

Additional Context

No response

Relevant log output

Organization

SAP Labs

Declaration

• I’m not disclosing any internal or sensitive information.

Start by reproducing the MultiComboBox invalid-input case in Safari with a screen reader, using the reported inputs such as "x" or "11". Compare the spoken output with the visible "invalid entry" message; done means the error is announced clearly and explains what went wrong and how to fix it.