docs(deps): Name the unblock condition on the JunitXml.TestLogger pin (#584)

States when the pin can be lifted: JunitXml.TestLogger 8.x requires
Microsoft.Testing.Platform v2, which xunit.v3 first supports in its 4.x
line, so the two bumps go together.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: petrsvihlik

Directory.Packages.props

@@ -86,9 +86,11 @@
     <PackageVersion Include="Aspire.Hosting.Testing" Version="13.4.4" />
     <PackageVersion Include="FakeItEasy" Version="9.0.1" />
     <!-- Emits JUnit XML test results for Codecov Test Analytics (flaky-test / failure
-         reporting). Consumed via the `junit` VSTest logger in CI. Pinned below 8.0.0:
-         that release links against Microsoft.Testing.Platform 2.0, which outranks the
-         1.9.1 pulled in transitively by xunit.v3 and breaks the build with CS1705. -->
+         reporting). Consumed via the `junit` VSTest logger in CI. Pinned below 8.0.0: the
+         8.x line is compiled against Microsoft.Testing.Platform v2, while xunit.v3 3.x
+         ships MTP 1.x, so mixing them breaks the build with CS1705 in every test project.
+         Bump to 8.x together with the xunit.v3 4.x upgrade — the first xunit line with
+         MTP v2 support. -->
     <PackageVersion Include="JunitXml.TestLogger" Version="7.1.0" />
     <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="10.0.9" />
     <PackageVersion Include="Microsoft.Extensions.Configuration" Version="10.0.9" />