lower expected embedded tool size again

src/BUILD

@@ -144,7 +144,7 @@ rule_size_test(
     # WARNING: Only adjust the number in `expect` if you are intentionally
     # adding or removing embedded tools. Know that the more embedded tools there
     # are in Bazel, the bigger the binary becomes and the slower Bazel starts.
-    expect = 408,
+    expect = 389,
     margin = 5,  # percentage
 )