Fix devcontainer build failure (#12837)

* add post-installation script

* set zsh as default terminal and make post-install execution on postcreate

* rename file

* rename script

* Create devcontainers_ci.yml

* Update devcontainer.json

* Update devcontainers_ci.yml

Never push image built here. It's for build testing purpose only.

* postCreateCommand update to reflect that the shell script has been renamed.

* update devcontainer readme file

* trigger workflow only on devcontainer/** changes

* prettier refactor