tests: remove redundant dune rules

[vbgl]

These rules are broken with dune 3.17.0

Fixes #35.

[bclement-ocp]

Thanks for the report and suggested fix! I don't really understand what changed in dune 3.17 to break this, and I will look into it, but you might know — you are saying these rules are redundant ; are they automatically introduced by the test rules now?

[vbgl]

Sorry, I don’t have any answer to your questions.

[Halbaroth]

Thanks for reporting the issue. It seems that Dune automatically generates these rules according to the documentation of tests:
https://dune.readthedocs.io/en/stable/reference/dune/test.html

This defines an executable named mytest.exe that will be executed as part of the runtest alias. If the directory also contains
an expect_test.expected file, then expect_test will be used to define an expect test. That is, the test will be executed and its
output will be compared to expect_test.expected.

This stanza has been added several years ago: ocaml/dune#822. There is no relation with the latest release but it seems that we did not use correctly this stanza. I guess Dune does not realize that the rule below needs to run after tests.

(rule
 (alias runtest)
 (action
  (diff solveEmpty.expected solveEmpty.output)
 )
)

I checked that tests are still running with your patch with Dune 3.16 and 3.17.

[vbgl]

Thanks!