[lldb][test] Modernize asserts (#82503)

This uses [teyit](https://pypi.org/project/teyit/) to modernize asserts,
as recommended by the [unittest release
notes](https://docs.python.org/3.12/whatsnew/3.12.html#id3).

For example, `assertTrue(a == b)` is replaced with `assertEqual(a, b)`.
This produces better error messages, e.g. `error: unexpectedly found 1
and 2 to be different` instead of `error: False`.

lldb/test/API/functionalities/scripted_process/TestScriptedProcess.py

@@ -201,9 +201,7 @@ class ScriptedProcesTestCase(TestBase):
 
         py_impl = process_0.GetScriptedImplementation()
         self.assertTrue(py_impl)
-        self.assertTrue(
-            isinstance(py_impl, dummy_scripted_process.DummyScriptedProcess)
-        )
+        self.assertIsInstance(py_impl, dummy_scripted_process.DummyScriptedProcess)
         self.assertFalse(hasattr(py_impl, "my_super_secret_member"))
         py_impl.my_super_secret_member = 42
         self.assertTrue(hasattr(py_impl, "my_super_secret_member"))