Force bin/dev overwrite to deal with new default bin/dev file

[jeromedalbert]

Ref: rails/rails#52433.

Fixes rails new myapp --main --css sass currently blocking, waiting for user input:

  Add bin/dev to start foreman
    conflict    bin/dev
  Overwrite /Users/jerome/c/rails/myapp/bin/dev? (enter "h" for help) [Ynaqdhm]

After merging this PR, it would be nice if a new release could be cut, so rails new myapp --main --css sass doesn't block.