Update for GE 6.0

[gerhardol]

PluginManager should be updated for GitExtensions 6.0 with .net9 and new extensiability
gitextensions/gitextensions.extensibility#33

Build fails though, Neptuo.Observables.Commands not found.
But no new version of Neptou since last build?

[RussKie]

/cc: @maraf

[maraf]

The Plugin Manager is using package Neptuo.Observables which is still on nuget.org https://www.nuget.org/packages/Neptuo.Observables in the version referenced by this project

Do you have a binlog?

[gerhardol]

Build just fails for me, namespace Neptuo.Observables.Commands is not available.

[maraf]

I see. It's trying to restore historical versions, like 1.0.0. Looks like CPM isn't working correctly.

[gerhardol]

Awaiting gitextensions/gitextensions.extensibility#33, then to test with #79 and something like my branch feature/ge6