Update dependency Tomlyn.Signed to 0.20.0 (#1655)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Directory.Packages.props

@@ -48,7 +48,7 @@
     <PackageVersion Include="System.Runtime.Loader" Version="4.3.0" />
     <PackageVersion Include="System.Text.Json" Version="9.0.10" />
     <PackageVersion Include="System.Threading.Tasks.Dataflow" Version="8.0.1" />
-    <PackageVersion Include="Tomlyn.Signed" Version="0.19.0" />
+    <PackageVersion Include="Tomlyn.Signed" Version="0.20.0" />
     <PackageVersion Include="yamldotnet" Version="15.3.0" />
     <PackageVersion Include="Faker.net" Version="2.0.163" />
     <PackageVersion Include="Valleysoft.DockerfileModel" Version="1.2.0" />