Remove unused concourse/* from source

This is a further update based on the PR:
 - #1625

Author: tuhaihe

pom.xml

@@ -571,8 +571,6 @@ code or new licensing patterns.
             <include>src/backend/gporca/**/Makefile</include>
 
             <exclude>src/backend/gporca/cmake/FindXerces.cmake</exclude>
-            <exclude>src/backend/gporca/concourse/build_and_test.py</exclude>
-            <exclude>src/backend/gporca/concourse/xerces-c/xerces-c-3.1.2.tar.gz.sha256</exclude>
             <exclude>src/backend/gporca/server/fixdxl.sh</exclude>
             <exclude>src/backend/gporca/server/include/unittest/gpopt/operators/CScalarIsDistinctFromTest.h</exclude>
             <exclude>src/backend/gporca/server/dxl.xsd</exclude>