[lldb] Fix Python test formatting (NFC)

All Python files in the LLVM repository were reformatted with Black [1].
Files inside the LLDB subproject were reformatted in 2238dcc393. This
patch updates a handful of tests that were added or modified since then
and weren't formatted with Black.

[1] https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style/68257

lldb/test/API/python_api/value/TestValueAPI.py

@@ -151,13 +151,17 @@ class ValueAPITestCase(TestBase):
         # smaller type to a larger as we often wouldn't know how to get the extra data:
         val_f = target.EvaluateExpression("f")
         bad_cast = val_s.Cast(val_f.GetType())
-        self.assertFailure(bad_cast.GetError(),
-                           "Can only cast to a type that is equal to or smaller than the orignal type.")
+        self.assertFailure(
+            bad_cast.GetError(),
+            "Can only cast to a type that is equal to or smaller than the orignal type.",
+        )
         weird_cast = val_f.Cast(val_s.GetType())
-        self.assertSuccess(weird_cast.GetError(),
-                        "Can cast from a larger to a smaller")
-        self.assertEqual(weird_cast.GetChildMemberWithName("a").GetValueAsSigned(0), 33,
-                         "Got the right value")
+        self.assertSuccess(weird_cast.GetError(), "Can cast from a larger to a smaller")
+        self.assertEqual(
+            weird_cast.GetChildMemberWithName("a").GetValueAsSigned(0),
+            33,
+            "Got the right value",
+        )
 
         # Check that lldb.value implements truth testing.
         self.assertFalse(lldb.value(frame0.FindVariable("bogus")))