Rationale for this change

To improve test run time by using rust’s aggressive compiler optimizations. This is generally done by testing multiple settings and levels, 1-2 could be done as well but the most improvement we get with this codebase is with 3. LTO and codegen unit numbers being 1 do not provide enough justification for build time increase, as they do not give good runtime improvements compared to this.

What changes are included in this PR?

Set the optimization level for test profile to 3 to improve test performance and potentially catch more optimization-related issues.

Are these changes tested?

Yes, manually.

/claim #557