Fix ros_test for pytest running

[JafarAbdi]

# TODO: Why this returns an empty string inside this function, it works when called outside
# parsed_output = call(
#     [
#         "python3",
#         "-m",
#         "pytest",
#         "--color=no",
#         "--collect-only",
#         "--quiet",
#         "--",
#         src_dir,
#     ]
# )
# for line in parsed_output.split("\n"):
#     if len(line) and not PATTERN.match(line):
#         tests.append(line + "@pytest")