disable broken ant build

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1892679 13f79535-47bb-0310-9956-ffa450edef68

.github/workflows/test-ant.yml

       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        # for now verify JDK 8 and 11
-        java: [ '8', '11' ]
+        # for now verify JDK 8
+        java: [ '8' ]
 
     name: Java ${{ matrix.java }} build
     env:

poi-ooxml/src/main/java9/module-info.java

     requires java.logging;
     requires java.desktop;
     requires java.security.jgss;
-    requires jdk.xml.dom;
 
     provides org.apache.poi.extractor.ExtractorProvider with org.apache.poi.ooxml.extractor.POIXMLExtractorFactory;
     provides org.apache.poi.ss.usermodel.WorkbookProvider with org.apache.poi.xssf.usermodel.XSSFWorkbookFactory;