Bump AkkaVersion from 1.4.18 to 1.4.19

Bumps `AkkaVersion` from 1.4.18 to 1.4.19.

Updates `Akka` from 1.4.18 to 1.4.19
- [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@1.4.18...1.4.19)

Updates `Akka.Serialization.Hyperion` from 1.4.18 to 1.4.19
- [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@1.4.18...1.4.19)

Updates `Akka.TestKit.Xunit2` from 1.4.18 to 1.4.19
- [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@1.4.18...1.4.19)

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

src/common.props

@@ -18,7 +18,7 @@
     <NoWarn>$(NoWarn);CS1591</NoWarn>
   </PropertyGroup>
   <PropertyGroup>
-    <AkkaVersion>1.4.18</AkkaVersion>
+    <AkkaVersion>1.4.19</AkkaVersion>
 
     <FluentAssertionsVersion>5.10.3</FluentAssertionsVersion>
     <XunitVersion>2.4.1</XunitVersion>