Bump mypy 0.950 (#939)

* Bump mypy to 0.95x

* Remove the * for inferred types

There was an upstream change (https://github.com/python/mypy/pull/12459)
to remove * from inferred types in the reveal_type output.

As we are asserting the * to exist, all the test cases are now failing
on the 0.950 release. Removing the expected * to mirror the upstream
behaviour change should resolve the test failures.

requirements.txt

@@ -10,4 +10,4 @@ psycopg2-binary
 -e .
 
 # Overrides:
-mypy==0.942
+mypy==0.950