gnu: python-markupsafe: Honor #:tests in check phase.

* gnu/pacakges/python-xyz.scm (python-markupsafe)[arguments]: Honor #:tests flag.

gnu/packages/python-xyz.scm

@@ -3757,8 +3757,9 @@ e.g. filters, callbacks and errbacks can all be promises.")
     (arguments
      `(#:phases (modify-phases %standard-phases
                   (replace 'check
-                    (lambda _
-                      (invoke "pytest" "-vv"))))))
+                    (lambda* (#:key tests? #:allow-other-keys)
+                      (when tests?
+                        (invoke "pytest" "-vv")))))))
     (native-inputs
      `(("python-pytest" ,python-pytest)))
     (home-page "https://github.com/mitsuhiko/markupsafe")