Optimize AssertIsLessOrEqual api

[lightning-li]

Description

Optimize the AssertIsLessOrEqual API by moving ToBinary into the code block where bConst is true. This change avoids one ToBinary constraint when both arguments of AssertIsLessOrEqual are variables.

Type of change

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

How has this been tested?

No new test cases have been added; use the existing relevant test cases

How has this been benchmarked?

• Benchmark A, on Macbook pro M1, 32GB RAM
• Benchmark B, on x86 Intel xxx, 16GB RAM

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I did not modify files generated from templates
• golangci-lint does not output errors locally
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[gbotrel]

lgtm, thanks for the contribution