test(auth): deprecated InputBox usage causes flakiness #6596

## Problem
#6594

The `getMfaCodeFromUser` currently uses a deprecated version of
`createInputBox` and the following `promptUser` function:

https://github.com/aws/aws-toolkit-vscode/blob/0fa1b5b47ab642458df934192832a4ffcb6c9d1e/packages/core/src/shared/ui/input.ts#L72-L135

Based on the stack trace, there is a race condition here that can lead
to a type error, but unsure how?
Stack trace: 
```
TypeError: inputBox.hide is not a function
      at promptUser (/Users/runner/work/aws-toolkit-vscode/aws-toolkit-vscode/packages/core/src/shared/ui/input.ts:133:18)
      at async getMfaTokenFromUser (/Users/runner/work/aws-toolkit-vscode/aws-toolkit-vscode/packages/core/src/auth/credentials/utils.ts:124:19)
      at async /Users/runner/work/aws-toolkit-vscode/aws-toolkit-vscode/packages/core/src/auth/providers/sharedCredentialsProvider.ts:422:38
```
### Investigation Notes:
- The error only happens when running the test suite as a whole. 
- The error only happens in CI (unable to reproduce locally). 

## Solution
- avoid use of deprecated `createInputBox`
[function](https://github.com/aws/aws-toolkit-vscode/blob/0fa1b5b47ab642458df934192832a4ffcb6c9d1e/packages/core/src/shared/ui/input.ts#L31-L58),
prefer new version instead.
- Ran the tests 4x with 1000x on the test, and did not see a failure. 

## Future Work 
- Migrate existing cases away from this deprecated `createInputBox` if
there is evidence it leads to flaky tests or unreliable behavior.

Author: Hweinstock

packages/core/src/auth/credentials/utils.ts

@@ -14,8 +14,9 @@ import { messages, showMessageWithCancel, showViewLogsMessage } from '../../shar
 import { Timeout, waitTimeout } from '../../shared/utilities/timeoutUtils'
 import { fromExtensionManifest } from '../../shared/settings'
 import { Profile } from './sharedCredentials'
-import { createInputBox, promptUser } from '../../shared/ui/input'
 import { openUrl } from '../../shared/utilities/vsCodeUtils'
+import { createInputBox } from '../../shared/ui/inputPrompter'
+import { isValidResponse } from '../../shared/wizards/wizard'
 
 const credentialsTimeout = 300000 // 5 minutes
 const credentialsProgressDelay = 1000
@@ -113,18 +114,16 @@ const errorMessageUserCancelled = localize('AWS.error.mfa.userCancelled', 'User
  */
 export async function getMfaTokenFromUser(mfaSerial: string, profileName: string): Promise<string> {
     const inputBox = createInputBox({
-        options: {
-            ignoreFocusOut: true,
-            placeHolder: localize('AWS.prompt.mfa.enterCode.placeholder', 'Enter Authentication Code Here'),
-            title: localize('AWS.prompt.mfa.enterCode.title', 'MFA Challenge for {0}', profileName),
-            prompt: localize('AWS.prompt.mfa.enterCode.prompt', 'Enter code for MFA device {0}', mfaSerial),
-        },
+        ignoreFocusOut: true,
+        placeholder: localize('AWS.prompt.mfa.enterCode.placeholder', 'Enter Authentication Code Here'),
+        title: localize('AWS.prompt.mfa.enterCode.title', 'MFA Challenge for {0}', profileName),
+        prompt: localize('AWS.prompt.mfa.enterCode.prompt', 'Enter code for MFA device {0}', mfaSerial),
     })
 
-    const token = await promptUser({ inputBox: inputBox })
+    const token = await inputBox.prompt()
 
     // Distinguish user cancel vs code entry issues with the error message
-    if (!token) {
+    if (!isValidResponse(token)) {
         throw new Error(errorMessageUserCancelled)
     }