Fix spelling in HostingPathResolver method names

[z0rimo]

• You've read the Contributor Guide and Code of Conduct.
• You've included unit or integration tests for your change, where applicable. (Not applicable: spelling-only change.)
• You've included inline docs for your change, where applicable. (Not applicable.)
• N/A — This is a spelling-only change and does not require an issue.

Fix spelling mistakes in private HostingPathResolver method names.

Description

Correct the following spelling mistakes:

• PathWithDirectorySeperatorAtEnd → PathWithDirectorySeparatorAtEnd
• ResolvePathNonCononical → ResolvePathNonCanonical

No functional changes.

[dotnet-policy-service]

Thanks for your PR, @z0rimo. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[Youssef1313]

LGTM