Revert "Added a test to cover the package migration."

This reverts commit 00b37a5.

Author: AswinRajGopal

Assets/Tests/InputSystem.Editor/CustomProcessorEnumTest.cs

@@ -108,31 +108,5 @@ public IEnumerator ProcessorEnum_ShouldSerializeByValue_WhenSerializedToAsset()
 
         yield return null;
     }
-    
-    [UnityTest]
-    public IEnumerator Migration_FromLegacyJson_ShouldConvertOrdinal_KeepInvertVector2_AndSeparators()
-    {
-        var legacyJson = m_Asset.ToJson().Replace("\"version\": 1", "\"version\": 0").Replace("Custom(SomeEnum=10)", "Custom(SomeEnum=1)");
-
-        // Add a trailing processor to verify the semicolon separator is preserved.
-        if (!legacyJson.Contains(";InvertVector2(invertX=true)"))
-            legacyJson = legacyJson.Replace("Custom(SomeEnum=1)\"", "Custom(SomeEnum=1);InvertVector2(invertX=true)\"");
-
-        var migratedAsset = InputActionAsset.FromJson(legacyJson);
-        Assume.That(migratedAsset, Is.Not.Null, "Failed to load legacy JSON into an InputActionAsset.");
-
-        var migratedJson = migratedAsset.ToJson();
-        Assume.That(migratedJson, Is.Not.Null.And.Not.Empty, "Migrated JSON was empty.");
-
-        Assert.Less(migratedJson.IndexOf("InvertVector2(invertX=true)", StringComparison.Ordinal), migratedJson.IndexOf(",Custom(SomeEnum=20)", StringComparison.Ordinal),
-            "Expected a comma between the first and second processors, with InvertVector2 first."
-        );
-
-        Assert.Greater(migratedJson.IndexOf(";InvertVector2(invertX=true)", StringComparison.Ordinal), migratedJson.IndexOf("Custom(SomeEnum=20)", StringComparison.Ordinal),
-            "Expected a semicolon between the second and third processors, with the trailing InvertVector2 last."
-        );
-
-        yield return null;
-    }
 }
 #endif