Bump coverlet.msbuild from 3.0.2 to 3.0.3 (#527)

Author: dependabot[bot]

Directory.Build.targets

@@ -35,7 +35,7 @@
     <PackageReference Update="Serilog.Sinks.XUnit" Version="2.0.4" />
     <PackageReference Update="XunitXml.TestLogger" Version="2.1.45" />
     <PackageReference Update="coverlet.collector" Version="3.0.2" />
-    <PackageReference Update="coverlet.msbuild" Version="3.0.2" />
+    <PackageReference Update="coverlet.msbuild" Version="3.0.3" />
     <PackageReference Update="System.Reactive" Version="4.4.1" />
     <PackageReference Update="System.Collections.Immutable" Version="1.7.1" />
     <PackageReference Update="Microsoft.Reactive.Testing" Version="4.4.1" />