Don't run baseline package validation during NuGet publishing for major version changes (OSOE-857)

[Piedone]

To allow breaking changes in major versions, something that the baseline package validator we use during NuGet publishing doesn't do (see dotnet/sdk#40907), let's not run it in such cases.

So, if New-NuGetPackage notices a major version change (e.g. from 1.2.3 to 2.0.0) then disable baseline package validation (but only that, package validation should otherwise run).

If dotnet/sdk#40907 is implemented before, then this won't be needed.

Jira issue

[Piedone]

@sarahelsaig wasn't this an issue for you for https://github.com/Lombiq/Helpful-Libraries/releases/tag/v10.0.0?

[sarahelsaig]

No, when I pushed a major tag it always worked.

[Piedone]

That's what I remembered doing before, but still, I had to do Lombiq/UI-Testing-Toolbox@803e87f to publish a new major version. It failed under https://github.com/Lombiq/UI-Testing-Toolbox/actions/runs/9100082776/job/25014098526 without it.