[red-knot] Fix bugs relating to assignability of dynamic type[] types (#14972)

crates/red_knot_python_semantic/resources/mdtest/type_of/dynamic.md

@@ -1,13 +1,20 @@
 # `type[Any]`
 
+This file contains tests for non-fully-static `type[]` types, such as `type[Any]` and
+`type[Unknown]`.
+
 ## Simple
 
 ```py
-def f(x: type[Any]):
+def f(x: type[Any], y: type[str]):
     reveal_type(x)  # revealed: type[Any]
     # TODO: could be `<object.__repr__ type> & Any`
     reveal_type(x.__repr__)  # revealed: Any
 
+    # type[str] and type[Any] are assignable to each other
+    a: type[str] = x
+    b: type[Any] = y
+
 class A: ...
 
 x: type[Any] = object
@@ -70,3 +77,26 @@ def test(x: Any, y: SomethingUnknown):
     reveal_type(y.__class__)  # revealed: type[Unknown]
     reveal_type(y.__class__.__class__.__class__.__class__)  # revealed: type[Unknown]
 ```
+
+## `type[Unknown]` has similar properties to `type[Any]`
+
+```py
+import abc
+from typing import Any
+from does_not_exist import SomethingUnknown  # error: [unresolved-import]
+
+has_unknown_type = SomethingUnknown.__class__
+reveal_type(has_unknown_type)  # revealed: type[Unknown]
+
+def test(x: type[str], y: type[Any]):
+    """Both `type[Any]` and `type[Unknown]` are assignable to all `type[]` types"""
+    a: type[Any] = x
+    b: type[str] = y
+    c: type[Any] = has_unknown_type
+    d: type[str] = has_unknown_type
+
+def test2(a: type[Any]):
+    """`type[Any]` and `type[Unknown]` are also assignable to all instances of `type` subclasses"""
+    b: abc.ABCMeta = a
+    b: abc.ABCMeta = has_unknown_type
+```