Fix ActiveIssue issue number to use full Url (dotnet#32182)

This is the only one in the repo still using a number.

src/libraries/System.Net.NetworkInformation/tests/FunctionalTests/NetworkInterfaceBasicTest.cs

@@ -53,7 +53,7 @@ public void BasicTest_AccessInstanceProperties_NoExceptions()
 
         [Fact]
         [PlatformSpecific(TestPlatforms.Linux)]  // Some APIs are not supported on Linux
-        [ActiveIssue(18090)]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/18090")]
         public void BasicTest_AccessInstanceProperties_NoExceptions_Linux()
         {
             foreach (NetworkInterface nic in NetworkInterface.GetAllNetworkInterfaces())