Fix unpredictable untyped simplification

When the type is not set, a dict is canonicalized by adding all types,
then trying to join them to remove the unnecessary values.

Because `_join` is not commutative or associative, the order of types
matters and cause variations in the canonicalized output.

If there are issues in some `_join` that cause errors, then the tests
become flaky, for instance the exception below only happens when
enumerating Jtypes start with `number` and is followed by `integer`.

(Any other order will first create a `JSONanyOf` that will only attempt
a real join on the `anyOf` alternatives if the types are identical
which won't call the failing code because `number` != `integer`).

```
Traceback (most recent call last):
  File "/home/runner/work/jsonsubschema/jsonsubschema/test/test_numeric.py", line 649, in test_all_all_3
    self.assertFalse(isSubschema(s2, s1))
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/api.py", line 56, in isSubschema
    s1, s2 = prepare_operands(s1, s2)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/api.py", line 46, in prepare_operands
    canonicalize_schema(s2))
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_canonicalization.py", line 35, in canonicalize_schema
    canonical_schema = canonicalize_dict(obj)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_canonicalization.py", line 84, in canonicalize_dict
    return canonicalize_connectors(d)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_canonicalization.py", line 218, in canonicalize_connectors
    allofs.append(canonicalize_dict({c: d[c]}))
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_canonicalization.py", line 84, in canonicalize_dict
    return canonicalize_connectors(d)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_canonicalization.py", line 211, in canonicalize_connectors
    simplified = simplify_schema_and_embed_checkers(d)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_canonicalization.py", line 369, in simplify_schema_and_embed_checkers
    allofs = [simplify_schema_and_embed_checkers(i) for i in s["allOf"]]
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_canonicalization.py", line 369, in <listcomp>
    allofs = [simplify_schema_and_embed_checkers(i) for i in s["allOf"]]
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_canonicalization.py", line 366, in simplify_schema_and_embed_checkers
    return boolToConstructor.get("anyOf")({"anyOf": anyofs})
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_checkers.py", line 1481, in JSONanyOfFactory
    ret = ret.join(i)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_checkers.py", line 133, in join
    ret = self._join(s)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_checkers.py", line 686, in _join
    return _joinNumber(self, s)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_checkers.py", line 672, in _joinNumber
    gcd = utils.gcd(s1.multipleOf, s2.multipleOf)
  File "/home/runner/work/jsonsubschema/jsonsubschema/jsonsubschema/_utils.py", line 269, in gcd
    return fractions.gcd(x, y)
AttributeError: module 'fractions' has no attribute 'gcd'
```

Author: kmichel-aiven

jsonsubschema/_canonicalization.py

@@ -91,7 +91,7 @@ def canonicalize_dict(d, outer_key=None):
     elif utils.is_list(t):
         return canonicalize_list_of_types(d)
     else:
-        d["type"] = definitions.Jtypes
+        d["type"] = sorted(definitions.Jtypes)
         return canonicalize_list_of_types(d)