Don't include unneeded Tomcat JARs

The platform build include the following JARs, which are redundant because they are already part of Tomcat itself:

• tomcat-coyote-9.0.20.jar
• tomcat-jdbc-9.0.20.jar
• tomcat-jni-9.0.20.jar
• tomcat-juli-9.0.20.jar (in $TOMCAT/bin)
• tomcat-util-9.0.20.jar

Note that we're already excluding, using various means, the following:

• tomcat-catalina-9.0.20.jar (named catalina.jar)
• tomcat-jasper-9.0.20.jar (named jasper.jar)