[static-runtime] clamp fast_sigmoid result into (0,1) range (#91993)
fast_sigmoid uses fast_tanh under the hood which is not precise;
the op outputs are treated as probability-like numbers;
in a reeeally small percentage of cases the outputs fell out of acceptable range for probabilities
Test Plan: ci
Differential Revision: D42445821
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91993
Approved by: https://github.com/davidberard98
