test: allow Snakemake tests to run on newer Python versions (#700)

After upgrading Snakemake to version 7.32.4 (reanahub/reana-commons#435)
there is no need to avoid running Snakemake tests on Python 3.11 and
3.12, as it should be supported.

Closes #655

Author: giuseppe-steduto

tests/test_cli_workflows.py

@@ -580,10 +580,6 @@ def test_create_snakemake_workflow_from_json_parameters(
     external_parameter_yaml_file,
 ):
     """Test create workflow from json with external parameters."""
-    if sys.version_info.major == 3 and sys.version_info.minor in (11, 12):
-        pytest.xfail(
-            "Snakemake features of reana-client are not supported on Python 3.11"
-        )
     status_code = 201
     response = {
         "message": "The workflow has been successfully created.",