tests/qtest/migration-test: Disable the analyze-migration.py test on s390x

The analyze-migration.py script fails on s390x hosts:

 Traceback (most recent call last):
   File "scripts/analyze-migration.py", line 662, in <module>
     dump.read(dump_memory = args.memory)
   File "scripts/analyze-migration.py", line 596, in read
     classdesc = self.section_classes[section_key]
 KeyError: ('s390-storage_attributes', 0)

It obviously never has been adapted to s390x yet, so until this
has been done, disable this test on s390x.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231018091239.164452-1-thuth@redhat.com>

tests/qtest/migration-test.c

@@ -3034,7 +3034,9 @@ int main(int argc, char **argv)
 
     qtest_add_func("/migration/bad_dest", test_baddest);
 #ifndef _WIN32
-    qtest_add_func("/migration/analyze-script", test_analyze_script);
+    if (!g_str_equal(arch, "s390x")) {
+        qtest_add_func("/migration/analyze-script", test_analyze_script);
+    }
 #endif
     qtest_add_func("/migration/precopy/unix/plain", test_precopy_unix_plain);
     qtest_add_func("/migration/precopy/unix/xbzrle", test_precopy_unix_xbzrle);