Bump AWSSDK.EC2 from 3.7.16.2 to 3.7.20.5

Bumps [AWSSDK.EC2](https://github.com/aws/aws-sdk-net) from 3.7.16.2 to 3.7.20.5.
- [Release notes](https://github.com/aws/aws-sdk-net/releases)
- [Changelog](https://github.com/aws/aws-sdk-net/blob/master/SDK.CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-net/commits)

---
updated-dependencies:
- dependency-name: AWSSDK.EC2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

src/discovery/Akka.Discovery.AwsApi/Akka.Discovery.AwsApi.csproj

@@ -9,7 +9,7 @@
 
     <ItemGroup>
       <PackageReference Include="Akka.Discovery" Version="1.4.21-beta1" />
-      <PackageReference Include="AWSSDK.EC2" Version="3.7.16.2" />
+      <PackageReference Include="AWSSDK.EC2" Version="3.7.20.5" />
       <PackageReference Include="AWSSDK.ECS" Version="3.7.2.13" />
     </ItemGroup>