Dune langage version and menhir version incompatible

[fblanqui]

07:39 ~/src/dedukti ((HEAD détachée sur 5990bc6c)) make install
File "dune-project", line 3, characters 14-17:
3 | (using menhir 2.0)
                  ^^^
Warning: Version 2.0 of the menhir extension is not supported until version
1.4 of the dune language.
Supported versions of this extension in version 1.2 of the dune language:
- 1.0
File "dune-project", line 3, characters 14-17:
3 | (using menhir 2.0)
                  ^^^
Warning: Version 2.0 of the menhir extension is not supported until version
1.4 of the dune language.
Supported versions of this extension in version 1.2 of the dune language:
- 1.0

07:41 ~/src/dedukti ((HEAD détachée sur 5990bc6c)) l dune-project 
(lang dune 1.2)
(name dedukti)
(using menhir 2.0)

Note that the current dune language version is >= 2.7. So 1.2 is very old.

[francoisthire]

I think it can be updated safely, we just need an MR ;)