Yii2: remove mockAssetManager (#3742)
Yii2: remove mockAssetManager (#3742)

* Yii2: remove mockAssetManager

* <3 for Nitpick-CI

janhenkgerritsen/Codeception,Naktibalda/Codeception,kt81/Codeception,hubbyist/Codeception,tasselchof/Codeception,janhenkgerritsen/Codeception,tasselchof/Codeception,Vreasy/Codeception,Naktibalda/Codeception,sergeyklay/Codeception,hubbyist/Codeception,tiger-seo/Codeception,pitpit/Codeception,Codeception/Codeception,tiger-seo/Codeception,Naktibalda/Codeception,kt81/Codeception,Codeception/base,Codeception/Codeception,Codeception/base,sergeyklay/Codeception,Vreasy/Codeception,Codeception/base,pitpit/Codeception,tasselchof/Codeception