Merge pull request #26497 from LnL7/fix-lib-tests

lib-tests: fix test for isStorePath

lib/tests/misc.nix

···
   testIsStorePath =  {
     expr =
       let goodPath =
-            "/nix/store/d945ibfx9x185xf04b890y4f9g3cbb63-python-2.7.11";
+            "${builtins.storeDir}/d945ibfx9x185xf04b890y4f9g3cbb63-python-2.7.11";
       in {
         storePath = isStorePath goodPath;
         storePathAppendix = isStorePath