Use the Bazel zip tool instead of the jar tool. (#623)

The jar tool is deprecated.

Author: gkdn

closure/repositories.bzl

@@ -702,8 +702,8 @@ def com_google_javascript_closure_compiler():
             "    name = \"externs\",",
             "    srcs = [\"%s\"]," % jar,
             "    outs = [\"externs.zip\"],",
-            "    tools = [\"@bazel_tools//tools/jdk:jar\"],",
-            "    cmd = \"$(location @bazel_tools//tools/jdk:jar) -xf $(location :%s) externs.zip; mv externs.zip $@\"," % jar,
+            "    tools = [\"@bazel_tools//tools/zip:zipper\"],",
+            "    cmd = \"$(location @bazel_tools//tools/zip:zipper) x $(location :%s) externs.zip; mv externs.zip $@\"," % jar,
             ")",
             "",
         ]),