More fixing breakage of the go rule tests.

The test itself is still failing. I don't understand why (seems to be the fixture that is wrong).

--
MOS_MIGRATED_REVID=108038743

tools/build_rules/go/BUILD

diff --git a/tools/build_rules/go/BUILD b/tools/build_rules/go/BUILD
index 4b9bebc..24d5589 100644
--- a/tools/build_rules/go/BUILD
+++ b/tools/build_rules/go/BUILD
@@ -8,5 +8,8 @@
         "//tools/build_rules/go/tools:srcs",
         "//tools/build_rules/go/toolchain:srcs",
     ],
-    visibility = ["//tools:__pkg__"],
+    visibility = [
+        "//src:__subpackages__",
+        "//tools:__pkg__",
+    ],
 )