Bump MvvmCross from 6.4.2 to 7.0.0 (#495)

Bumps [MvvmCross](https://github.com/MvvmCross/MvvmCross) from 6.4.2 to 7.0.0.
- [Release notes](https://github.com/MvvmCross/MvvmCross/releases)
- [Changelog](https://github.com/MvvmCross/MvvmCross/blob/develop/CHANGELOG.md)
- [Commits](MvvmCross/MvvmCross@6.4.2...7.0.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

SpotifyAPI.Web.Examples/Example.UWP/Example.UWP.csproj

@@ -157,7 +157,7 @@
       <Version>6.2.10</Version>
     </PackageReference>
     <PackageReference Include="MvvmCross">
-      <Version>6.4.2</Version>
+      <Version>7.0.0</Version>
     </PackageReference>
   </ItemGroup>
   <ItemGroup>