Github token needed for CI when downloading executables

[bdestombe]

Also required by flopy tests: https://github.com/modflowpy/flopy/blob/388ac8d484b08ae26a57793759bae22dd0db21fb/.github/workflows/mf6.yml#L81

edit: suppressing checking version of exe during tests instead of adding github token

[bdestombe]

The reason it is suddenly exceeding the interaction rate github allows without github token is because now the version of modflow is often checked; upon most calls of get_exe_path(). This PR includes a way to suppress the version checking by setting an environment variable, which is now used in the github CI.

[OnnoEbbens]

I am back from the holidays and saw many improvements so I might not be completely up to date. Do I understand correctly that every time you call get_exe_path() using the default options a check is done to see if your local modflow executable is the latest version? And then these checks are done so many times that interaction rate is exceeded?

If that is correct than I am wondering if we really want to do this check every time. I personally almost never want to download the newest executable when I call the get_exe_path function. I just want to use the one that I've used before. So instead of setting an environment variable can we not make enable_version_check=False by default?

[bdestombe]

Hi Onno,
Thanks for having a look :)

So I looked it up. You can do 60 requests per hour to the github website without account/token. That means 1 time downloading and 59 times converting "latest" to "18.0". And is called with every to_model_ds(), so this is indeed not feasible. I'll change it.

[bdestombe]

Okay, so now the defaults are configured such that only when you pass the version_tag command the version is checked.

If you explicitely pass the version_tag "latest" an API call is made, and when this version is not already installed on your PC, another API call is made to download the executables. If the version_tag is set to for example "18.0" this first API call is not required.

@OnnoEbbens could you have a look at the PR?

[OnnoEbbens]

Looks good to me. Only thing I don't understand yet is why you need the environment variable SUPPRESS_EXE_VERION_CHECK. I would think we can do without the environment variable now the default is not to check the version number. Do I miss something?