mypy

d8418599 - Properly support union of TypedDicts as dict literal context (#14505)

Properly support union of TypedDicts as dict literal context (#14505) Fixes #14481 (regression) Fixes #13274 Fixes #8533 Most notably, if literal matches multiple items in union, it is not an error, it is only an error if it matches none of them, so I adjust the error message accordingly. An import caveat is that an unrelated error like `{"key": 42 + "no"}` can cause no item to match (an hence an extra error), but I think it is fine, since we still show the actual error, and avoiding this would require some dirty hacks. Also note there was an (obvious) bug in one of the fixtures, that caused one of repros not repro in tests, fixing it required tweaking an unrelated test.