bayesian_optimization version to 2.0.4 and use Acquisition function instead of utility function

[gauravmanmode]

Upgrade bayesian_optimization version to 2.0.4 and use Acquisition function instead of utility function

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Motivation and Context / Related issue

bayesian_optimization==1.4.0 is pinned strictly in requirements/main.txt
Trying to install newer versions of bayesian_optimization>=1.4.0 and nevergrad>1.0.3 causes conflict issues.

Linked issue #1701

How Has This Been Tested (if it applies)

Checklist

• The documentation is up-to-date with the changes I made.
• I have read the CONTRIBUTING document and completed the CLA (see CLA).
• All tests passed, and additional code has been covered with new tests.