Added derivative and Hessian for Ackley test function

[stefan-k]

No description provided.

[codecov-commenter]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (fcfda30) 91.33% compared to head (647384b) 91.39%.

Files	Patch %	Lines
crates/argmin-testfunctions/src/ackley.rs	98.85%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #447      +/-   ##
==========================================
+ Coverage   91.33%   91.39%   +0.05%     
==========================================
  Files         162      162              
  Lines       21238    21404     +166     
==========================================
+ Hits        19398    19562     +164     
- Misses       1840     1842       +2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.