Fix SyntaxError warning in regexp after Python 3.12

Python 3.12 is stricter about regular expression: as the character `?` has no special meaning within squared brackets, escaping it is ambiguous.

pymrio/tools/ioutil.py

@@ -659,7 +659,7 @@ def filename_from_url(url):
         The extracted file name
 
     """
-    name = re.search("[^/\\&\?]+\.\w{2,7}(?=([\?&].*$|$))", url)
+    name = re.search("[^/\\&?]+\.\w{2,7}(?=([\?&].*$|$))", url)
     return name.group()