Bump rules_apple version to 0.13.0

Should resolve travis/buildkite test issues.

PiperOrigin-RevId: 231802544
diff --git a/WORKSPACE b/WORKSPACE
index 1860cda..880887f 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 git_repository(
     name = "build_bazel_rules_apple",
     remote = "https://github.com/bazelbuild/rules_apple.git",
-    tag = "0.11.1",
+    tag = "0.13.0",
 )
 
 load(