Remove .yaml suffix from test names (#809)

This commit fixes a regression in which the `.yaml` suffix is
incorrectly appended to the names of tests, introduced when support
for suites directories was added.

lib/pavilion/config.py

@@ -264,7 +264,7 @@ def suite_info(self) -> List[Tuple[str, str, Path]]:
 
             if tests_dir.exists():
                 tests = [file for file in tests_dir.iterdir() if file.suffix.lower() == ".yaml"]
-                names = [test.name for test in tests]
+                names = [test.stem for test in tests]
                 labels = [label] * len(tests)
 
                 suite_infos.extend(zip(labels, names, tests))