Remove reference to java_tools for jdk15 since it doesn't exist yet

Author: Jonpez2

src/BUILD

@@ -769,9 +769,6 @@ filegroup(
         "@remote_java_tools_javac14_test_darwin//:WORKSPACE",
         "@remote_java_tools_javac14_test_linux//:WORKSPACE",
         "@remote_java_tools_javac14_test_windows//:WORKSPACE",
-        "@remote_java_tools_javac15_test_darwin//:WORKSPACE",
-        "@remote_java_tools_javac15_test_linux//:WORKSPACE",
-        "@remote_java_tools_javac15_test_windows//:WORKSPACE",
         "@remote_java_tools_linux_for_testing//:WORKSPACE",
         "@remote_java_tools_windows_for_testing//:WORKSPACE",
         "@remotejdk11_linux_aarch64_for_testing//:WORKSPACE",