Circuit Disposal Before DotNetInvoke Causes Unhandled NullReferenceException

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Describe the bug

While investigating #45638, we found that JSInterop DotNet Invocation is being called on a circuit that has already been disposed from an exception during a RegExAttribute validation, which causes a `NullReferenceException`. While the particular `System.Format` error was caused by user error (unescaped curly braces which get parsed as empty formatting), there shouldn't be invocations on an already disposed circuit.

### Expected Behavior

There may need to be a restructure or added check(s) to ensure that the circuit is expected to be not null for the entirety of the invocation.

### Steps To Reproduce

https://github.com/Nick-Stanton/RegExCircuitCrash - Modified from the submitted repro in #45638

- Take note of the first RegEx in `Data\DataAnnotationsTest.cs` to see what may be invalidated.
- Launch app and navigate to "Data annotation test"
- Enter something invalid into the left text box (e.g. the character '=')

### Exceptions (if any)

In order of first appearance:

- System.FormatException: 'Input string was not in a correct format.'
- System.Reflection.TargetInvocationException: 'Exception has been thrown by the target of an invocation.'
- System.OperationCanceledException: 'The operation was canceled.'
- System.Threading.Tasks.TaskCanceledException: 'A task was canceled.'
- System.NullReferenceException: 'Object reference not set to an instance of an object.'

### .NET Version

6.0+, untested on earlier versions

### Anything else?

_No response_