gnu: python-platformdirs: Update to 2.4.0, run tests and fix metadata.

* gnu/packages/python-xyz.scm (python-platformdirs): Update to 2.4.0.
[phases]{pretend-version}: New phase.
{check}: Override to run tests.
[native-inputs]{python-setuptools-scm}: New input.

gnu/packages/python-xyz.scm

@@ -27499,17 +27499,30 @@ (define-public python-stripe
 (define-public python-platformdirs
   (package
     (name "python-platformdirs")
-    (version "2.2.0")
+    (version "2.4.0")
     (source
      (origin
        (method url-fetch)
        (uri (pypi-uri "platformdirs" version))
        (sha256
-        (base32 "07hq5qrp7pqj63iczg01wbf5ii6f0ncd0dq5mzkdhsslmg9slbb3"))))
+        (base32 "1whycrymqpsl7nsaknmcybzyh4fg4kqk6vd7zwl28kfhnf05wyin"))))
     (build-system python-build-system)
+    (arguments
+     `(#:phases
+       (modify-phases %standard-phases
+         (add-before 'build 'pretend-version
+           ;; The version string is usually derived via setuptools-scm, but
+           ;; without the git metadata available, the version string is set to
+           ;; '0.0.0'.
+           (lambda _
+             (setenv "SETUPTOOLS_SCM_PRETEND_VERSION" ,version)))
+         (replace 'check
+           (lambda* (#:key tests? #:allow-other-keys)
+             (when tests?
+               (invoke "pytest")))))))
     (native-inputs
      (list python-appdirs python-pytest python-pytest-cov
-           python-pytest-mock))
+           python-pytest-mock python-setuptools-scm))
     (home-page "https://github.com/platformdirs/platformdirs")
     (synopsis "Determine the appropriate platform-specific directories")
     (description "When writing applications, finding the right location to