`SimpleDecoder.__getitem__` incorrectly validates exclusive [stop] of Python slice

Library version: PyNvVideoCodec 2.1.0 (pip, pynvvideocodec==2.1.0)

Bug:
SimpleDecoder.__getitem__ calls self.validate_index(key.stop) on the exclusive stop of a Python slice. This raises IndexError when stop == len(decoder), which is the normal Python convention for "all remaining elements."

Location: SimpleDecoder.py, lines 88–94

elif isinstance(key, slice):
    indices = range(key.start, key.stop, key.step)  # stop is exclusive here ✓
    idxs = list(iter(indices))
    if not idxs:
        raise ValueError(f"Invalid input.")
    self.validate_index(key.start)
    self.validate_index(key.stop)      # ← BUG: validates exclusive stop as if inclusive
    return self.simple_decoder[idxs]

Reproduce:

import PyNvVideoCodec as nvc

dec = nvc.SimpleDecoder("any_video.mp4", output_color_type=nvc.OutputColorType.RGB)
n = len(dec)       # e.g. 107
frames = dec[0:n:1]  # IndexError: Index 107 is out of range [0, 106]

Expected: dec[0:n:1] should return all n frames, consistent with standard Python slice semantics where stop is exclusive.

Fix:
self.validate_index(key.stop - 1). Also, I'd probably move the self.validate(key.start) and self.validate(key.stop) before the whole range to list to reduce unnecessary computation before you know the range is safe.

Start in SimpleDecoder.py at lines 88–94 and inspect how slice bounds are validated after building idxs. Reproduce the issue with dec[0:len(dec):1], then verify that the exclusive stop at len(dec) returns all frames without IndexError.