Rather than passing a power value of 1 to the scale op, send None.

[SandSnip3r]

Description

Rather than passing 1 for the exponent for the scale op, pass None. This will save a wasteful elementwise pow op being run.
This also prevents us from hitting a bug in TensorRT-RTX where pow(x,y) where x is negative returns NaN.

Fixes #3699

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project (You can use the linters)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas and hacks
• I have made corresponding changes to the documentation
• I have added tests to verify my fix or my feature
• New and existing unit tests pass locally with my changes
• I have added the relevant labels to my PR in so that relevant reviewers are notified

[apbose]

LGTM. I assume the test_cumsum_aten cudaErrorIllegalAddress errors in RTX are unrelated to this PR