refactor: removed pre-MN_RR logic of validation of CL

[knst]

Issue being fixed or feature implemented

The fork MN_RR is active awhile on testnet and mainnet and no more need legacy check

What was done?

Removes legacy version of checks for CL and related functional tests

How Has This Been Tested?

Run unit / functional test - DONE Reindex testnet - DONE Reindex mainnet - DONE

Breaking Changes

Removed pre-mn_rr version of checks for CL. It's no more relevant on mainnet and testnet. It affects behavior on new devnets and regtest for pre-mn_rr activation blocks.

Checklist:

• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have added or updated relevant unit/integration/functional/e2e tests
• [x] I have made corresponding changes to the documentation
• [x] I have assigned this pull request to a milestone

[PastaPastaPasta]

I ran feature_llmq_chainlocks.py ~30 times without issue (with tsan / debug) locally