Add rms_norm operator

[voltjia]

pytest output:

============================= test session starts ==============================
platform linux -- Python 3.10.12, pytest-8.3.3, pluggy-1.5.0
rootdir: /home/huangjiacheng/ntops
configfile: pyproject.toml
plugins: cov-6.0.0
collected 366 items

tests/test_abs.py ........                                               [  2%]
tests/test_add.py ........                                               [  4%]
tests/test_addmm.py ..                                                   [  4%]
tests/test_bitwise_and.py ................                               [  9%]
tests/test_bitwise_not.py ................                               [ 13%]
tests/test_bitwise_or.py ................                                [ 18%]
tests/test_bmm.py ..                                                     [ 18%]
tests/test_clamp.py ........                                             [ 20%]
tests/test_cos.py ........                                               [ 22%]
tests/test_div.py ........                                               [ 25%]
tests/test_dropout.py ........                                           [ 27%]
tests/test_eq.py ........                                                [ 29%]
tests/test_exp.py ........                                               [ 31%]
tests/test_ge.py ........                                                [ 33%]
tests/test_gelu.py ........                                              [ 36%]
tests/test_gt.py ........                                                [ 38%]
tests/test_isinf.py ........                                             [ 40%]
tests/test_isnan.py ........                                             [ 42%]
tests/test_le.py ........                                                [ 44%]
tests/test_lt.py ........                                                [ 46%]
tests/test_mm.py ..                                                      [ 47%]
tests/test_mul.py ........                                               [ 49%]
tests/test_ne.py ........                                                [ 51%]
tests/test_neg.py ........                                               [ 54%]
tests/test_pow.py ........                                               [ 56%]
tests/test_relu.py ........                                              [ 58%]
tests/test_rms_norm.py ................................................. [ 71%]
...............                                                          [ 75%]
tests/test_rsqrt.py ........                                             [ 78%]
tests/test_scaled_dot_product_attention.py ............................. [ 86%]
...                                                                      [ 86%]
tests/test_sigmoid.py ........                                           [ 89%]
tests/test_silu.py ........                                              [ 91%]
tests/test_sin.py ........                                               [ 93%]
tests/test_softmax.py ........                                           [ 95%]
tests/test_sub.py ........                                               [ 97%]
tests/test_tanh.py ........                                              [100%]

======================= 366 passed in 2147.56s (0:35:47) =======================