fix: support pytest on python 3.12 wrt Fraction formatting change

python 3.12 supports float-style formatting for Fraction by
python/cpython#100161 .
With this change, when ":n" format specifier is used in format() for
Fraction type, this now raises ValueError instead of previous
TypeError.

To make pytest succeed with python 3.12, make
pint.testing.assert_allclose also rescue ValueError .

Fixes #1818 .

pint/testing.py

@@ -64,7 +64,7 @@ def assert_allclose(
     if msg is None:
         try:
             msg = f"Comparing {first!r} and {second!r}. "
-        except TypeError:
+        except (TypeError, ValueError):
             try:
                 msg = f"Comparing {first} and {second}. "
             except Exception: