Remove unused `clear_association_cache`
Remove unused `clear_association_cache`

It is no longer used since #41112.

yahonda/rails,bogdanvlviv/rails,Edouard-chin/rails,yahonda/rails,lcreid/rails,georgeclaghorn/rails,MSP-Greg/rails,Stellenticket/rails,EmmaB/rails-1,kddeisz/rails,bogdanvlviv/rails,esparta/rails,Erol/rails,Erol/rails,yahonda/rails,Vasfed/rails,kddeisz/rails,lcreid/rails,kddeisz/rails,Envek/rails,Vasfed/rails,Envek/rails,bogdanvlviv/rails,Edouard-chin/rails,Envek/rails,BlakeWilliams/rails,Stellenticket/rails,kmcphillips/rails,EmmaB/rails-1,joonyou/rails,Erol/rails,MSP-Greg/rails,joonyou/rails,BlakeWilliams/rails,Edouard-chin/rails,esparta/rails,yawboakye/rails,BlakeWilliams/rails,yawboakye/rails,Edouard-chin/rails,rails/rails,yawboakye/rails,rails/rails,MSP-Greg/rails,kddeisz/rails,georgeclaghorn/rails,MSP-Greg/rails,joonyou/rails,Erol/rails,georgeclaghorn/rails,lcreid/rails,joonyou/rails,rails/rails,Stellenticket/rails,kmcphillips/rails,yawboakye/rails,esparta/rails,kmcphillips/rails,kmcphillips/rails,georgeclaghorn/rails,rails/rails,BlakeWilliams/rails,Vasfed/rails,Stellenticket/rails,lcreid/rails,EmmaB/rails-1,esparta/rails,Vasfed/rails,bogdanvlviv/rails,Envek/rails,yahonda/rails