chore: add a comment referencing the issue

Author: Aghassi

js/private/js_binary.bzl

@@ -640,6 +640,8 @@ the contract between Bazel and a test runner.""",
             default = Label("//js/private/coverage:merger"),
             cfg = "exec",
         ),
+        # Solves for the situation where a js_binary is passed to a js_test
+        # @see https://github.com/aspect-build/rules_js/pull/1486
         "_is_test": attr.bool(
             default = True
         )