refactor(fetcher): migrate withRetries to waitUntil (#6429)

## Problem
Recently a
[PR](https://github.com/aws/aws-toolkit-vscode/pull/6387/files#diff-c0100187095b7c009b33063c21a517248290b37d02ef10e9370d28cd3ed5d1ea)
on master combined `waitUntil` with `withRetries`. Once master merged
into feature branch, it caused this case to start erroring.

Leading to the following:
```
npm error src/shared/resourcefetcher/httpResourceFetcher.ts(164,16): error TS2304: Cannot find name 'withRetries'.
```

## Solution
- migrate to `waitUntil` in the same fashion as the PR. 

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: Hweinstock

packages/core/src/shared/resourcefetcher/httpResourceFetcher.ts

@@ -135,7 +135,7 @@ export class HttpResourceFetcher implements ResourceFetcher<Response> {
 }
 
 export class RetryableResourceFetcher extends HttpResourceFetcher {
-    private readonly retryNumber: number
+    private readonly requestTimeoutMs: number
     private readonly retryIntervalMs: number
     private readonly resource: string
 
@@ -155,13 +155,13 @@ export class RetryableResourceFetcher extends HttpResourceFetcher {
             showUrl,
             timeout,
         })
-        this.retryNumber = retryNumber
+        this.requestTimeoutMs = retryNumber * retryIntervalMs
         this.retryIntervalMs = retryIntervalMs
         this.resource = resource
     }
 
     fetch(versionTag?: string) {
-        return withRetries(
+        return waitUntil(
             async () => {
                 try {
                     return await this.getNewETagContent(versionTag)
@@ -171,8 +171,9 @@ export class RetryableResourceFetcher extends HttpResourceFetcher {
                 }
             },
             {
-                maxRetries: this.retryNumber,
-                delay: this.retryIntervalMs,
+                timeout: this.requestTimeoutMs,
+                interval: this.retryIntervalMs,
+                retryOnFail: true,
             }
         )
     }