Modify to install tensorflow-macos for M1/M2 Mac

[yuzie007]

Thank you so much developers for sharing the code, which helps me quite a lot for jumping into ML-potential researches!

Short description

This modification allows us to install tensorpotential also in M1/M2 Mac.

Long description

The original tensorflow (as of 2.12.0) seems not available for M1/M2 Mac; we cannot find a wheel for M1/M2 Mac in PyPI (https://pypi.org/project/tensorflow/2.12.0/#files), and indeed I obtained the following error message;

% pip install tensorflow
ERROR: Could not find a version that satisfies the requirement tensorflow (from versions: none)
ERROR: No matching distribution found for tensorflow

Apple, instead, offers their own optimized tensorflow in a different name, tensorflow-macos (see https://developer.apple.com/metal/tensorflow-plugin/). To use this, however, we need to specify tensorflow-macos instead of tensorflow in install_requires.

For a simple specification of a platform, we may be able to use environment markers, but to specify M1/M2 Mac, it seems more straightforward to use the platform library.