Fix: syntax errors and undefined references in CUTEst benchmarks

[AJ0070]

This PR cleans up and fixes issues in CUTEst benchmark files:

• CUTEst_unconstrained.jmd
  Removed a block of raw Julia code (lines 16–41) that was placed outside of any code fence. This appears to have been a copy-paste error of analysis code that should only run after the benchmarks.

• CUTEst_quadratic.jmd
  Removed a duplicate code fragment (lines 112–117) that was located outside the main function definition.

• CUTEst_unbounded.jmd
  Fixed an invalid call to run_unbounded_benchmarks, which does not exist, and replaced it with the correct function call to run_benchmarks.

  AI Disclosure: Manually reviewed the code, Used Chatgpt to rephrase the PR description and convert into markdown

  Part of CUTEST.jl benchmark wrappers #935

[AJ0070]

@ChrisRackauckas

[AJ0070]

I’m currently reviewing older PRs to understand the past changes.