check-meta: remove support for meta.tests

this nerver worked as meta can not contain derivations
and this required the tests to be derivations
lets just not allow this.

Also tests now days are set in passthru.tests,
so even if it would work, we are already using a diffrent convention.

This was introduced in https://github.com/NixOS/nixpkgs/pull/44439
Allowing derivations in meta issue https://github.com/NixOS/nix/issues/2532

pkgs/stdenv/generic/check-meta.nix

@@ -373,15 +373,6 @@ let
       unfree = bool;
       unsupported = bool;
       insecure = bool;
-      tests = {
-        name = "test";
-        verify =
-          x:
-          x == { }
-          ||
-            # Accept {} for tests that are unsupported
-            (isDerivation x && x ? meta.timeout);
-      };
       timeout = int;
       knownVulnerabilities = listOf str;
       badPlatforms = platforms;