[LTC] Autogen `rsqrt` and `sigmoid` for TS backend (#66133)
Summary:
This commit adds code-gen support for rsqrt and sigmoid.
Test Plan:
test/cpp/build/test_ptltc --gtest_filter=AtenLtcTsTensorTest.TestRsqrt*
test/cpp/build/test_ptltc --gtest_filter=AtenLtcTsTensorTest.TestSigmoid*
