[syntax-errors] await outside async functions (#17363)

Summary
--

This PR implements detecting the use of `await` expressions outside of
async functions. This is a reimplementation of
[await-outside-async
(PLE1142)](https://docs.astral.sh/ruff/rules/await-outside-async/) as a
semantic syntax error.

Despite the rule name, PLE1142 also applies to `async for` and `async
with`, so these are covered here too.

Test Plan
--

Existing PLE1142 tests.

I also deleted more code from the `SemanticSyntaxCheckerVisitor` to
avoid changes in other parser tests.

crates/ruff_linter/resources/test/fixtures/pylint/await_outside_async.py

@@ -72,3 +72,15 @@ def await_generator_target():
 # See: https://github.com/astral-sh/ruff/issues/14167
 def async_for_list_comprehension_target():
     [x for x in await foo()]
+
+
+def async_for_dictionary_comprehension_key():
+    {await x: y for x, y in foo()}
+
+
+def async_for_dictionary_comprehension_value():
+    {y: await x for x, y in foo()}
+
+
+def async_for_dict_comprehension():
+    {x: y async for x, y in foo()}