Adapt to coq/coq#19620 (Global.push_context_set no strict argument)

[SkySkimmer]

No description provided.

[ppedrot]

Please merge now.

[ppedrot]

Ping @JasonGross

[JasonGross]

This is not backwards compatible, it's failing with

File "src/Rewriter/Util/plugins/inductive_from_elim.ml", line 48, characters 10-12:
48 |       let () = Global.push_context_set ctx in
               ^^
Error: This pattern should not be a unit literal, the expected type is
       strict:bool -> unit

on the Alpine CI. Are you sure we should be changing the older versions of the code too?