remove soak test cauldron

Author: Ruslan Gustomiasov

test/BUILD

@@ -21,7 +21,6 @@ filegroup(
         "//test/integration:all-srcs",
         "//test/kubemark:all-srcs",
         "//test/list:all-srcs",
-        "//test/soak/cauldron:all-srcs",
         "//test/soak/serve_hostnames:all-srcs",
         "//test/typecheck:all-srcs",
         "//test/utils:all-srcs",