Remove `.bd-example-responsive-containers`
Remove `.bd-example-responsive-containers`

Added in https://github.com/twbs/bootstrap/pull/29095/files#diff-d4fb29267ed3a7c27482bbeac1723ab6 but never used
GerHobbelt/bootstrap,tjkohli/bootstrap,coliff/bootstrap,twbs/bootstrap,m5o/bootstrap,tjkohli/bootstrap,zalog/bootstrap,inway/bootstrap,zalog/bootstrap,twbs/bootstrap,GerHobbelt/bootstrap,GerHobbelt/bootstrap,zalog/bootstrap,coliff/bootstrap,m5o/bootstrap,inway/bootstrap,inway/bootstrap