[TASK] Avoid direct MySQL mention in README.md

TYPO3 works with various DBMS. Avoid a specific
mention of MySQL in README.md, the version matrix
reveals details.

Releases: main, 12.4
Resolves: #103719
Change-Id: I38cc50be00838643cb0095b3c848ef1d8a0c3014
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84015


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>

README.md

@@ -9,7 +9,7 @@ This document provides a basic introduction to TYPO3.
 Getting Started
 ---------------
 
-TYPO3 requires a web server with PHP and a database (e.g. MySQL).
+TYPO3 requires a web server with PHP and a database.
 The backend is accessed via a supported browser.
 
 Please see the [Installation Guide](https://docs.typo3.org/installation)