[Build] Remove Maven prerequisites intended for maven-plugin projects

Removing the prerequisites removes the warning, which states:
'''
The project org.eclipse:eclipse-platform-parent:pom:4.40.0-SNAPSHOT uses
prerequisites which is only intended for maven-plugin projects but not
for non maven-plugin projects. For such purposes you should use the
maven-enforcer-plugin.
'''

Author: HannesWell

eclipse-platform-parent/pom.xml

@@ -21,9 +21,6 @@
   <artifactId>eclipse-platform-parent</artifactId>
   <version>4.40.0-SNAPSHOT</version>
   <packaging>pom</packaging>
-  <prerequisites>
-    <maven>3.9.9</maven>
-  </prerequisites>
   <properties>
     <!-- As of Tycho 0.22, skipTests takes priority, if maven.test.skip also specified,
       with different value. See https://bugs.eclipse.org/442976.