Merge all changes

src/Attestor/__Tests/StellaOps.Attestor.Verify.Tests/AttestorVerificationEngineTests.cs

@@ -319,7 +319,21 @@ public sealed class AttestorVerificationEngineTests
     }
 
     private static X509Certificate2 EnsurePrivateKey(X509Certificate2 certificate, ECDsa key)
-        => certificate.HasPrivateKey ? certificate : certificate.CopyWithPrivateKey(key);
+    {
+        if (certificate.HasPrivateKey)
+        {
+            return certificate;
+        }
+
+        try
+        {
+            return certificate.CopyWithPrivateKey(key);
+        }
+        catch (InvalidOperationException)
+        {
+            return certificate;
+        }
+    }
 
     private static string ToPem(X509Certificate2 certificate)
     {