[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.

commandsv3/CMakeLists.txt

@@ -1,53 +0,0 @@
-project(commandsv3)
-
-include(SubDirList)
-include(CompileWarnings)
-include(AddTest)
-
-if(WITH_JAVA)
-    include(UseJava)
-
-    file(GLOB_RECURSE JAVA_SOURCES src/main/java/*.java src/generated/main/java/*.java)
-    file(GLOB QUICKBUF_JAR ${WPILIB_BINARY_DIR}/wpiutil/thirdparty/quickbuf/*.jar)
-
-    add_jar(
-        commandsv3_jar
-        ${JAVA_SOURCES}
-        INCLUDE_JARS
-            datalog_jar
-            hal_jar
-            ntcore_jar
-            cscore_jar
-            cameraserver_jar
-            wpiannotations_jar
-            wpimath_jar
-            wpiunits_jar
-            wpiutil_jar
-            wpilibj_jar
-            ${QUICKBUF_JAR}
-        OUTPUT_NAME commandsv3
-        OUTPUT_DIR ${WPILIB_BINARY_DIR}/${java_lib_dest}
-    )
-
-    install_jar(commandsv3_jar DESTINATION ${java_lib_dest})
-    install_jar_exports(
-        TARGETS commandsv3_jar
-        FILE commandsv3_jar.cmake
-        DESTINATION share/commandsv3
-    )
-endif()
-
-if(WITH_JAVA_SOURCE)
-    include(UseJava)
-    include(CreateSourceJar)
-    add_source_jar(
-        commandsv3_src_jar
-        BASE_DIRECTORIES
-            ${CMAKE_CURRENT_SOURCE_DIR}/src/main/java
-            ${CMAKE_CURRENT_SOURCE_DIR}/src/generated/main/java
-        OUTPUT_NAME commandsv3-sources
-        OUTPUT_DIR ${WPILIB_BINARY_DIR}/${java_lib_dest}
-    )
-    set_property(TARGET commandsv3_src_jar PROPERTY FOLDER "java")
-    install_jar(commandsv3_src_jar DESTINATION ${java_lib_dest})
-endif()

commandsv3/commandsv3-config.cmake.in

@@ -1,15 +0,0 @@
-include(CMakeFindDependencyMacro)
-@WPIUTIL_DEP_REPLACE@
-@DATALOG_DEP_REPLACE@
-@NTCORE_DEP_REPLACE@
-@CSCORE_DEP_REPLACE@
-@CAMERASERVER_DEP_REPLACE@
-@HAL_DEP_REPLACE@
-@WPILIBC_DEP_REPLACE@
-@WPIMATH_DEP_REPLACE@
-
-@FILENAME_DEP_REPLACE@
-include(${SELF_DIR}/commandsv3.cmake)
-if(@WITH_JAVA@)
-    include(${SELF_DIR}/commandsv3_jar.cmake)
-endif()