python3Packages.dbus-python: fix build when doInstallCheck=false

previously, tests are built regardless of `doCheck`/`doInstallCheck`,
but they depend on the `dbus` in `nativeCheckInputs`, breaking the
package for platforms which disable check phase (e.g. cross
compilation). so, properly avoid building tests when the check phase is
disabled.

pkgs/development/python-modules/dbus-python/default.nix

@@ -67,6 +67,12 @@ buildPythonPackage rec {
     "-Cbuild-dir=_meson-build"
   ];
 
+  preConfigure = ''
+    if [ -z "$doInstallCheck" ]; then
+      export mesonFlags="$mesonFlags -Dtests=false"
+    fi
+  '';
+
   # workaround bug in meson-python
   # https://github.com/mesonbuild/meson-python/issues/240
   postInstall = ''