chore: update jobserver tests to use check

tests/testsuite/jobserver.rs

@@ -55,7 +55,7 @@ fn jobserver_exists() {
     // Explicitly use `-j2` to ensure that there's eventually going to be a
     // token to read from `validate` above, since running the build script
     // itself consumes a token.
-    p.cargo("build -j2").run();
+    p.cargo("check -j2").run();
 }
 
 #[cargo_test]