Remove clone

It's no longer needed

src/Umbraco.Core/Security/UmbracoBackOfficeIdentity.cs

@@ -14,7 +14,7 @@ namespace Umbraco.Core.Security
     {
         // TODO: Ideally we remove this class and only deal with ClaimsIdentity as a best practice. All things relevant to our own
         // identity are part of claims. This class would essentially become extension methods on a ClaimsIdentity for resolving
-        // values from it. 
+        // values from it.
         public static bool FromClaimsIdentity(ClaimsIdentity identity, out UmbracoBackOfficeIdentity backOfficeIdentity)
         {
             // validate that all claims exist
@@ -214,19 +214,5 @@ namespace Umbraco.Core.Security
         public string SecurityStamp => this.FindFirstValue(Constants.Security.SecurityStampClaimType);
 
         public string[] Roles => FindAll(x => x.Type == DefaultRoleClaimType).Select(role => role.Value).ToArray();
-
-        /// <summary>
-        /// Overridden to remove any temporary claims that shouldn't be copied
-        /// </summary>
-        /// <returns></returns>
-        public override ClaimsIdentity Clone()
-        {
-            var clone = base.Clone();
-
-            foreach (var claim in clone.FindAll(x => x.Type == Constants.Security.TicketExpiresClaimType).ToList())
-                clone.RemoveClaim(claim);
-
-            return clone;
-        }
     }
 }

src/Umbraco.Tests.UnitTests/Umbraco.Core/BackOffice/UmbracoBackOfficeIdentityTests.cs

@@ -126,22 +126,5 @@ namespace Umbraco.Tests.UnitTests.Umbraco.Core.BackOffice
             Assert.AreEqual(12, identity.Claims.Count());
             Assert.IsNull(identity.Actor);
         }
-
-        [Test]
-        public void Clone()
-        {
-            var securityStamp = Guid.NewGuid().ToString();
-
-            var identity = new UmbracoBackOfficeIdentity(
-                "1234", "testing", "hello world", new[] { 654 }, new[] { 654 }, "en-us", securityStamp, new[] { "content", "media" }, new[] { "admin" });
-
-            // this will be filtered out during cloning
-            identity.AddClaim(new Claim(Constants.Security.TicketExpiresClaimType, "test"));
-
-            ClaimsIdentity cloned = identity.Clone();
-            Assert.IsNull(cloned.Actor);
-
-            Assert.AreEqual(10, cloned.Claims.Count());
-        }
     }
 }