Update dispatcher immutable files to 2.0.91 and enforcer plugin to unify md5 checksums

[froesef]

Description

Updates the immutable files to dispatcher sdk version 2.0.91. Also updates the enforcer plugin version so that there is no need for separate linux and windows checksums.

Related Issue

Motivation and Context

How Has This Been Tested?

I deployed the wknd site on an AEM sandbox.

Screenshots (if appropriate):

Types of changes

• [ ] 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)

Checklist:

• [x] I have signed the Adobe Open Source CLA.
• [ ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.