chore: align net10.0 package versions with CPM and drop redundant overrides

Bump Microsoft.Extensions.Http to 10.0.9 in Directory.Packages.props so the
central version matches the other net10.0 dependencies.

Remove VersionOverride from net10.0 PackageReference items in
Dependencies.props; those versions are already defined in CPM. Keep
VersionOverride on net8.0 and net9.0 where per-TFM versions still differ
from the central package versions.

Author: devlead

src/Devlead.Testing.MockHttp/Devlead.Testing.MockHttp.Dependencies.props

@@ -21,10 +21,9 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net10.0'">
-    <PackageReference Include="Verify.Http" VersionOverride="7.5.1" />
-    <PackageReference Include="Microsoft.Extensions.Http" VersionOverride="10.0.8" />
-    <PackageReference Include="Microsoft.Net.Http.Headers" VersionOverride="10.0.9" />
-    <PackageReference Include="Microsoft.Extensions.TimeProvider.Testing" VersionOverride="10.7.0" />
+    <PackageReference Include="Verify.Http" />
+    <PackageReference Include="Microsoft.Extensions.Http" />
+    <PackageReference Include="Microsoft.Net.Http.Headers" />
+    <PackageReference Include="Microsoft.Extensions.TimeProvider.Testing" />
   </ItemGroup>
-
 </Project>

src/Directory.Packages.props

@@ -11,7 +11,7 @@
     <PackageVersion Include="coverlet.collector" Version="10.0.1" />
     <PackageVersion Include="Microsoft.Extensions.TimeProvider.Testing" Version="10.7.0" />
     <PackageVersion Include="Microsoft.Net.Http.Headers" Version="10.0.9" />
-    <PackageVersion Include="Microsoft.Extensions.Http" Version="10.0.8" />
+    <PackageVersion Include="Microsoft.Extensions.Http" Version="10.0.9" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.7.0" />
     <PackageVersion Include="MimeTypes" Version="2.5.2" />
     <PackageVersion Include="NUnit" Version="4.6.1" />