Remove David Strauss as maintainer for MySQL DB driver subsystem

Problem/Motivation
David Strauss did not respond to the 2025 Annual Core Maintainer Check-In and has been unresponsive throughout the 4-week confirmation period.

As per the Core subsystem maintainer policy, maintainers who do not confirm their continued involvement will be removed from MAINTAINERS.txt.

Proposed resolution:
Remove David Strauss’s name and contact details from the MAINTAINERS.txt entry for the MySQL DB driver subsystem.

Remaining tasks:

• Commit the update to MAINTAINERS.txt
• Notify the Core Committers Slack channel when merged

No UI/API/Data model changes.