Fix tests for now-deprecated stylus package.

The last version of stylus published did not contain a version of the
caching-compiler package that these tests now depend on, so I've removed
the extra architecture matching for the stylus package (not for less).

tools/tests/apps/caching-stylus/.meteor/packages

@@ -4,6 +4,6 @@
 # but you can also edit it by hand.
 
 meteor-base
-stylus
+stylus@~2.513.13
 local-pack
 standard-minifiers

tools/tests/compiler-plugins.js

@@ -146,7 +146,8 @@ selftest.define("compiler plugin caching - coffee", () => {
       cacheMatch(
         "Ran (#" + nextRunOrdinal++ + ") on: " +
           JSON.stringify(files) +
-          (arch ? " " + JSON.stringify([arch]) : "")
+          ((arch && packageName !== "stylus")
+           ? " " + JSON.stringify([arch]) : "")
       );
     }