Remove WP 6.0 related code since it's deprecated now

[rebeccahum]

Description

Clean up code that is related to WP 6.0 since that's not available on our platform anymore. Also adds 6.6 in preparation for the 6.7 release

Pre-review checklist

Please make sure the items below have been covered before requesting a review:

• [ ] This change works and has been tested locally or in Codespaces (or has an appropriate fallback).
• [ ] This change works and has been tested on a sandbox.
• [ ] This change has relevant unit tests (if applicable).
• [ ] This change uses a rollout method to ease with deployment (if applicable - especially for large scale actions that require writes).
• [ ] This change has relevant documentation additions / updates (if applicable).
• [ ] I've created a changelog description that aligns with the provided examples.

Pre-deploy checklist

• [ ] VIP staff: Ensure any alerts added/updated conform to internal standards (see internal documentation).

Steps to Test

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 30.42%. Comparing base (0dc7c3b) to head (0fad109). Report is 22 commits behind head on develop.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #5978 +/- ## ============================================= + Coverage 30.41% 30.42% +0.01% Complexity 4813 4813 ============================================= Files 288 288 Lines 21136 21122 -14 ============================================= - Hits 6428 6426 -2 + Misses 14708 14696 -12 ```

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