Orleans.SyncWork release for .net7

What's Changed

• Orleans v7 upgrade by @htxryan in #37
• Use NUGET_KEY instead of NUGET_API_KEY secret by @ReubenBond in #39

New Contributors

• @htxryan made their first contribution in #37
• @ReubenBond made their first contribution in #39

Full Changelog: v1.5.9...v7.0.1