[BUG] VideoRecorder Crashes When Passing fps

[AlexandreBrown]

Describe the bug

Creating an instance of VideoRecorder crashes when we pass fps.

To Reproduce

from torchrl.record import VideoRecorder
VideoRecorder(None, None, "", None, fps=1)

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/mila/b/browna/.conda/envs/maniskill3_env/lib/python3.10/site-packages/torchrl/record/recorder.py", line 127, in __init__
    self.video_kwargs["fps"] = fps
  File "/home/mila/b/browna/.conda/envs/maniskill3_env/lib/python3.10/site-packages/torch/nn/modules/module.py", line 1928, in __getattr__
    raise AttributeError(
AttributeError: 'VideoRecorder' object has no attribute 'video_kwargs'

Expected behavior

No crash

System info

Describe the characteristic of your environment:

• Describe how the library was installed (pip, source, ...) torchrl==0.7.1
• Python version 3.10

print(torchrl.__version__, numpy.__version__, sys.version, sys.platform)
0.7.1 1.26.4 3.10.14 | packaged by conda-forge | (main, Mar 20 2024, 12:45:18) [GCC 12.3.0] linux

Checklist

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• I have provided a minimal working example to reproduce the bug (required)