typo in error type

[2e0byo]

oops, we have a type s/RunTimeError/RuntimeError/

  File "/home/john/code/16-channel/.venv/lib/python3.11/site-packages/skidl/tools/kicad/kicad.py", line 752, in _parse_lib_part_kicad_v6
    part_defn = parse_sexp(self.part_defn, allow_underflow=True)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/john/code/16-channel/.venv/lib/python3.11/site-packages/skidl/utilities.py", line 833, in parse_sexp
    raise RunTimeError("Bracketing mismatch!")
          ^^^^^^^^^^^^
NameError: name 'RunTimeError' is not defined. Did you mean: 'RuntimeError'?

(and I've messed up editing a file).

[2e0byo]

hmm I think there's another bug here: the error clearly says 'bracketing mismatch' which I'd naively assume meant too many of one of ( or ). But in fact the error is caused by changing the name of a symbol so it doesn't match one of property "value" or the inner symbol (prob. the former). So at the very least this error should be clearer.

I need to prove a proper MWE for this test.