Fix version switcher when building with Dune.
Fix version switcher when building with Dune.

Closes #12395.

ejgallego/coq,silene/coq,gares/coq,SkySkimmer/coq,ejgallego/coq,ejgallego/coq,SkySkimmer/coq,SkySkimmer/coq,Zimmi48/coq,ejgallego/coq,gares/coq,Zimmi48/coq,JasonGross/coq,silene/coq,gares/coq,Zimmi48/coq,gares/coq,JasonGross/coq,gares/coq,coq/coq,Zimmi48/coq,coq/coq,silene/coq,coq/coq,coq/coq,JasonGross/coq,SkySkimmer/coq,JasonGross/coq