internal/outcome: attempt nscd path-hiding if present

This avoids creating the mount point on musl setups which accomplishes nothing and can run into permission problems.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/outcome/run_test.go

@@ -710,7 +710,7 @@ func (k *stubNixOS) lookupEnv(key string) (string, bool) {
 func (k *stubNixOS) stat(name string) (fs.FileInfo, error) {
 	switch name {
 	case "/var/run/nscd":
-		return nil, nil
+		return stubFileInfoIsDir(true), nil
 	case "/run/user/1971/pulse":
 		return nil, nil
 	case "/run/user/1971/pulse/native":