[build] Remove cmake Java support (#8952)

This is increasingly difficult to maintain, and has very limited
benefit. Modern coprocessors with enough horsepower to run Java
applications can use the Gradle or Bazel build systems instead.

cmake/modules/CreateSourceJar.cmake

@@ -1,33 +0,0 @@
-macro(add_source_jar target)
-    set(oneValueArgs OUTPUT_NAME OUTPUT_DIR)
-    cmake_parse_arguments(SOURCE_JAR "" "${oneValueArgs}" "BASE_DIRECTORIES" ${ARGN})
-    foreach(base_package_dir ${SOURCE_JAR_BASE_DIRECTORIES})
-        file(GLOB_RECURSE directories LIST_DIRECTORIES true ${base_package_dir}/*.directoriesonly)
-        # Find all packages
-        foreach(directory ${directories})
-            cmake_path(
-                RELATIVE_PATH directory
-                BASE_DIRECTORY ${base_package_dir}
-                OUTPUT_VARIABLE package_name
-            )
-            file(GLOB package_sources ${directory}/*.java)
-            if(package_sources STREQUAL "")
-                continue()
-            endif()
-            # If package sources are scattered across different places, consolidate them under one package
-            list(FIND packages ${package_name} index)
-            if(index EQUAL -1)
-                list(APPEND packages ${package_name})
-            endif()
-            list(APPEND ${package_name} ${package_sources})
-        endforeach()
-    endforeach()
-    set(resources "")
-    foreach(package ${packages})
-        string(APPEND resources "NAMESPACE \"${package}\" ${${package}} ")
-    endforeach()
-    cmake_language(
-        EVAL CODE
-            "add_jar(${target} RESOURCES ${resources} OUTPUT_NAME ${SOURCE_JAR_OUTPUT_NAME} OUTPUT_DIR ${SOURCE_JAR_OUTPUT_DIR})"
-    )
-endmacro()