[torchlib] Deprecate Rank and IsScalar

[justinchuby]

Deprecate Rank and IsScalar and remove all usages. Do not remove the definitions because older versions of PyTorch assumes their existance.

[codecov]

Codecov Report

❌ Patch coverage is 96.29630% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 70.39%. Comparing base (59c3d32) to head (3334eda).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
onnxscript/function_libs/torch_lib/ops/core.py	95.45%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2624      +/-   ##
==========================================
+ Coverage   70.30%   70.39%   +0.08%     
==========================================
  Files         222      222              
  Lines       26276    26275       -1     
  Branches     2624     2629       +5     
==========================================
+ Hits        18474    18496      +22     
+ Misses       6885     6859      -26     
- Partials      917      920       +3     

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