[iOS] Skip PublicPrivateKey_IndependentLifetimes_DSA test (#96685)

DSA is not supported

Author: steveisok

src/libraries/System.Security.Cryptography/tests/X509Certificates/CertTests.cs

@@ -137,6 +137,7 @@ public static void PublicPrivateKey_IndependentLifetimes_RSA()
         }
 
         [Fact]
+        [SkipOnPlatform(PlatformSupport.MobileAppleCrypto, "DSA is not available")]
         public static void PublicPrivateKey_IndependentLifetimes_DSA()
         {
             X509Certificate2 loaded;