upgrade to ML.NET 1.5.1

[Gani Nazirov (ganik)]

No description provided.

[Kleber (klesouza)]

Sorry to step into this PR. I was just curious to know if you guys have plans to merge this PR soon. ML.NET 1.5.1 has some fixes I was interested to see available in NimbusML.

[Gani Nazirov (ganik)]

Sorry to step into this PR. I was just curious to know if you guys have plans to merge this PR soon. ML.NET 1.5.1 has some fixes I was interested to see available in NimbusML.

Kleber (@klesouza) Which fixes you are looking for in ML.NET ?

[Kleber (klesouza)]

Gani Nazirov (@ganik), I run into some problems regarding handling of categorical features in LightGBM. I looked around in ML.NET repo and found fixes for that in later versions (dotnet/machinelearning#5048)
The error I'm getting is: 'Categorical split features is zero length'

[Gani Nazirov (ganik)]

Kleber (@klesouza) there are few regressions we found in ML.NET 1.5.1 that need to be fixed. They will come in next ML.NET release. So we are targeting it. Also fyi there is no active development on NimbusML anymore. Only critical bug fixes/patches.