[quant] adding const qualifier to Quantizer::equalTo (#75355)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/75355
fix issue #74538 Quantizer::equalTo missing const qualifier
Equality test should be const.
Test Plan: Imported from OSS
Reviewed By: vkuzo
Differential Revision: D35444203
fbshipit-source-id: 41fed8d3768c70092995efab37a230a8f3f329a1
(cherry picked from commit 75844d8e3c6c624b524f562dc0932af853c2c2b5)
