Following the default value of the config CheckUserEnableSpecialInvestigate being set to true, Special:Investigate is now enabled on all installs unless specifically disabled. This config could be removed as no longer needed as there isn't a case where Special:Investigate needs to be disabled on a wiki.
To allow integration of Special:InvestigateBlock with Special:CheckUser 'get users' (T329493) it must not be possible to disable the use of Special:InvestigateBlock through a config. As such, removal this configuration blocks that task.
Acceptance criteria
- Remove the CheckUserEnableSpecialInvestigate config, replacing relevant code to always enable Special:Investigate