[ty] Minor tweaks to "list all members" docs and tests (#18388)

Ref https://github.com/astral-sh/ruff/pull/18251#pullrequestreview-2881810681

crates/ty_python_semantic/resources/mdtest/binary/in.md

@@ -23,13 +23,11 @@ x = ("quux", "bar", "baz")
 static_assert("foo" not in x)
 ```
 
-## Statically unknown results in a type error
+## Statically unknown results in a `bool`
 
 ```py
-from ty_extensions import static_assert
-
 def _(a: str, b: str):
-    static_assert("foo" in (a, b))  # error: [static-assert-error]
+    reveal_type("foo" in (a, b))  # revealed: bool
 ```
 
 ## Values being unknown doesn't mean the result is unknown
@@ -46,8 +44,6 @@ def _(a: int, b: int):
 ## Failure cases
 
 ```py
-from ty_extensions import static_assert
-
 # We don't support byte strings.
-static_assert(b"foo" not in (b"quux", b"foo", b"baz"))  # error: [static-assert-error]
+reveal_type(b"foo" not in (b"quux", b"foo", b"baz"))  # revealed: bool
 ```

crates/ty_python_semantic/resources/mdtest/ide_support/all_members.md

@@ -4,8 +4,8 @@
 
 <!-- snapshot-diagnostics -->
 
-The `ty_extensions.all_members` function allows access to a list of accessible members/attributes on
-a given object. For example, all member functions of `str` are available on `"a"`:
+The `ty_extensions.all_members` function allows access to a tuple of accessible members/attributes
+on a given object. For example, all member functions of `str` are available on `"a"`:
 
 ```py
 from ty_extensions import all_members, static_assert