Bump AkkaVersion from 1.4.3 to 1.4.8 (#108)

Bumps `AkkaVersion` from 1.4.3 to 1.4.8.

Updates `Akka` from 1.4.3 to 1.4.8
- [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@1.4.3...1.4.8)

Updates `Akka.TestKit.Xunit2` from 1.4.3 to 1.4.8
- [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@1.4.3...1.4.8)

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]

src/common.props

@@ -14,7 +14,7 @@
     <XunitVersion>2.4.1</XunitVersion>
     <TestSdkVersion>16.5.0</TestSdkVersion>
     <NBenchVersion>2.0.1</NBenchVersion>
-    <AkkaVersion>1.4.3</AkkaVersion>
+    <AkkaVersion>1.4.8</AkkaVersion>
     <NetCoreTestVersion>netcoreapp3.1</NetCoreTestVersion>
     <NetFrameworkTestVersion>net461</NetFrameworkTestVersion>
     <NetStandardLibVersion>netstandard2.0</NetStandardLibVersion>