Fix typos.

src/Avalonia.Base/AvaloniaObject.cs

@@ -331,7 +331,7 @@ namespace Avalonia
                 else
                 {
                     throw new NotSupportedException(
-                        "Canot set property to Unset at non-local value priority.");
+                        "Cannot set property to Unset at non-local value priority.");
                 }
             }
             else if (!(value is DoNothingType))

src/Avalonia.Base/Data/BindingValue.cs

@@ -161,7 +161,7 @@ namespace Avalonia.Data
                     new BindingNotification(Error, BindingErrorType.DataValidationError),
                 BindingValueType.DataValidationErrorWithFallback =>
                     new BindingNotification(Error, BindingErrorType.DataValidationError, Value),
-                _ => throw new NotSupportedException("Invalida BindingValueType."),
+                _ => throw new NotSupportedException("Invalid BindingValueType."),
             };
         }