chore(deps): update dotnet monorepo to v9 (#20)

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

Author: renovate[bot]

global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
     "rollForward": "latestMajor",
-    "version": "8.0.411"
+    "version": "9.0.301"
   }
 }

src/JamieMagee.MicrosoftSecurityUpdates.Client/JamieMagee.MicrosoftSecurityUpdates.Client.csproj

@@ -11,8 +11,8 @@
   </ItemGroup>
 
   <ItemGroup Label="Package References">
-    <PackageReference Include="Microsoft.Extensions.Http" Version="8.0.1" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.2" />
+    <PackageReference Include="Microsoft.Extensions.Http" Version="9.0.6" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="9.0.6" />
   </ItemGroup>
 
 </Project>