fix(Docker): add cache to dockerignore to speed up local build  (#4366)
fix(Docker): add cache to dockerignore to speed up local build  (#4366)

Apparently including cmake cache to the build context will take a long time for consecutive builds and causes docker build to spend a long time at `Sending build context to docker daemon (x %)` step.
mygithome002/azerothcore-wotlk,mygithome002/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Helias/azerothcore-wotlk,azerothcore/azerothcore-wotlk,mygithome002/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Helias/azerothcore-wotlk,Helias/azerothcore-wotlk,mygithome002/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,Helias/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Helias/azerothcore-wotlk,azerothcore/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Helias/azerothcore-wotlk,Nefertumm/azerothcore-wotlk