Improve support for PyTorch 2.* and Python>=3.8

[lrzpellegrini]

• Moves many imports from typing-extensions to typing. This also fixes the multiple inheritance issue (at least on Python 3.8). Only TypeAlias imports are kept because they are needed for Python<3.10.
• Removes ctrl-benchmark from the conda definition file due to ctrl-benchmark having a strict torch<2 dependency
  • This should also fix the recent issues in the CI: by installing ctrl-benchmark, PyTorch was replaced with a cuda pip version (thus ignoring conda's cpuonly).
    Related: https://discuss.pytorch.org/t/modulenotfounderror-no-module-named-torch-dynamo/193014