CI: allow_failure for fiat_crypto_ocaml
CI: allow_failure for fiat_crypto_ocaml

Failing since https://gitlab.com/coq/coq/-/jobs/2537542809 (the PR's
CI succeeded https://gitlab.com/coq/coq/-/jobs/2527415579)

ejgallego/coq,coq/coq,Zimmi48/coq,SkySkimmer/coq,coq/coq,Zimmi48/coq,SkySkimmer/coq,coq/coq,Zimmi48/coq,ejgallego/coq,coq/coq,Zimmi48/coq,ejgallego/coq,SkySkimmer/coq,ejgallego/coq,SkySkimmer/coq