containers-data 3.11 tests are broken on ocaml 5.1

```

\#=== ERROR while compiling containers-data.3.11 ===============================#
\# context              2.2.0~alpha3~dev | linux/x86_64 | ocaml-base-compiler.5.1.0 | file:///home/opam/opam-repository
\# path                 ~/.opam/5.1/.opam-switch/build/containers-data.3.11
\# command              ~/.opam/opam-init/hooks/sandbox.sh build dune runtest -p containers-data -j 127
\# exit-code            1
\# env-file             ~/.opam/log/containers-data-7-36628e.env
\# output-file          ~/.opam/log/containers-data-7-36628e.out
\### output ###
\# (cd _build/default && /home/opam/.opam/5.1/bin/ocamlc.opt -w -40 -strict-sequence -warn-error -a+8 -open CCShims_ -g -bin-annot -I tests/data/.t.eobjs/byte -I /home/opam/.opam/5.1/lib/bytes -I /home/opam/.opam/5.1/lib/containers -I /home/opam/.opam/5.1/lib/containers/monomorphic -I /home/opam/.opam/5.1/lib/either -I /home/opam/.opam/5.1/lib/gen -I /home/opam/.opam/5.1/lib/iter -I /home/opam/.opam/5.1/lib/ocaml/unix -I /home/opam/.opam/5.1/lib/qcheck-core -I /home/opam/.opam/5.1/lib/seq -I src/data/.containers_data.objs/byte -I src/testlib/.containers_testlib.objs/byte -no-alias-deps -open Dune__exe -o tests/data/.t.eobjs/byte/dune__exe__T_bitfield.cmo -c -impl tests/data/t_bitfield.ml)
\# File "tests/data/t_bitfield.ml", line 6, characters 15-33:
\# 6 | let module B = CCBitField.Make () in
\#                    ^^^^^^^^^^^^^^^^^^
\# Error: The functor was expected to be applicative at this position
\# (cd _build/default && src/mdx_runner.exe)
\# ocaml-mdx returned 0 ✔
```

Signed-off-by: Marcello Seri <[email protected]>

Author: mseri

packages/containers-data/containers-data.3.11/opam

@@ -5,7 +5,7 @@ license: "BSD-2-Clause"
 build: [
   ["dune" "build" "-p" name "-j" jobs]
   ["dune" "build" "@doc" "-p" name ] {with-doc}
-  ["dune" "runtest" "-p" name "-j" jobs] {with-test & arch != "x86_32" & arch != "arm32"}
+  ["dune" "runtest" "-p" name "-j" jobs] {with-test & arch != "x86_32" & arch != "arm32" & ocaml:version < "5.1.0"}
 ]
 depends: [
   "ocaml" { >= "4.03.0" }