remove redundant Count() in GlobalPackageFolderRepositories

[SimonCropp]

Bug

Fixes:

Description

remove redundant Count() in GlobalPackageFolderRepositories. faster to use the property. Also removes null check, since if it is null it would blow up in folders.AddRange(pathContext.FallbackPackageFolders);

PR Checklist

• Meaningful title, helpful description and a linked NuGet/Home issue
• Added tests
• Link to an issue or pull request to update docs if this PR changes settings, environment variables, new feature, etc.

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