Bump AkkaVersion from 1.4.27 to 1.4.28 (#230)

Bumps `AkkaVersion` from 1.4.27 to 1.4.28.

Updates `Akka.TestKit.XUnit2` from 1.4.27 to 1.4.28
- [Release notes](https://github.com/akkadotnet/akka.net/releases)
- [Changelog](https://github.com/akkadotnet/akka.net/blob/dev/RELEASE_NOTES.md)
- [Commits](akkadotnet/akka.net@1.4.27...1.4.28)

Updates `Akka.Cluster` from 1.4.27 to 1.4.28
- [Release notes](https://github.com/akkadotnet/akka.net/releases)
- [Changelog](https://github.com/akkadotnet/akka.net/blob/dev/RELEASE_NOTES.md)
- [Commits](akkadotnet/akka.net@1.4.27...1.4.28)

---
updated-dependencies:
- dependency-name: Akka.TestKit.XUnit2
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: Akka.Cluster
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/common.props

@@ -22,7 +22,7 @@ Upgraded to [Petabridge.Cmd v0.8.5](https://cmd.petabridge.com/articles/RELEASE_
     <NetStandardVersion>netstandard1.6</NetStandardVersion>
     <NetFrameworkLibVersion>net461</NetFrameworkLibVersion>
     <NetFrameworkTestVersion>net461</NetFrameworkTestVersion>
-    <AkkaVersion>1.4.27</AkkaVersion>
+    <AkkaVersion>1.4.28</AkkaVersion>
     <PbmVersion>0.8.5</PbmVersion>
   </PropertyGroup>
 </Project>