build: Remove System.Private.Uri (no longer used)

This was only added to address vulnerability scan, but this package is
no longer implicitly referenced.

src/Directory.Packages.props

@@ -53,7 +53,6 @@
   <!-- Following found during vulerabilities Code Scan  -->
   <ItemGroup>
     <PackageVersion Include="System.Net.Http" Version="4.3.4" />
-    <PackageVersion Include="System.Private.Uri" Version="4.3.2" />
     <PackageVersion Include="System.Text.RegularExpressions" Version="4.3.1" />
   </ItemGroup>
 </Project>

src/Recyclarr/Recyclarr.csproj

@@ -20,7 +20,6 @@
   <!-- Following found during vulerabilities Code Scan  -->
   <ItemGroup>
     <PackageReference Include="System.Net.Http" />
-    <PackageReference Include="System.Private.Uri" />
     <PackageReference Include="System.Text.RegularExpressions" />
   </ItemGroup>