test(vscode): fix failure to close editors on beforeEach hook. (#5975)

## Problem
- See #5325
- the following `waitUntil` is timing out:
https://github.com/aws/aws-toolkit-vscode/blob/43299f368308b6720ba22bbd910c6714bc47bdcb/packages/core/src/test/testUtil.ts#L495-L518
- All occurrences of error (AFAIK) fail to list any editors open. This
implies `waitUntil` is timing out even though all editors (that aren't
ignored by pattern) are closed.

## Solution
A potential explanation is that the `executeCommand` is taking a long
time to close the editors ignored by the patterns, and causing a timeout
in `waitUntil`. In this case, we don't want to error.
- refactor to also check if activeEditors is cleared. If there aren't
any, we shouldn't be throwing an error.
- Also, decrease timeout to avoid wasting time here during tests (if we
can't close ignored editors, don't waste time trying). This code is run
between every test so 5 second timeout per test is huge.

---

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packages/core/src/test/testUtil.ts

@@ -490,30 +490,30 @@ export async function closeAllEditors(): Promise<void> {
         /amazonwebservices\.[a-z\-]+-vscode\./,
         /nullExtensionDescription./, // Sometimes exists instead of the prior line, see https://github.com/aws/aws-toolkit-vscode/issues/4658
     ]
-    const editors: vscode.TextEditor[] = []
+    const editorsToClose: vscode.TextEditor[] = []
 
     const noVisibleEditor: boolean | undefined = await waitUntil(
         async () => {
             // Race: documents could appear after the call to closeAllEditors(), so retry.
             await vscode.commands.executeCommand(closeAllCmd)
-            editors.length = 0
-            editors.push(
+            editorsToClose.length = 0
+            editorsToClose.push(
                 ...vscode.window.visibleTextEditors.filter(
                     (editor) => !ignorePatterns.some((p) => p.test(editor.document.fileName))
                 )
             )
 
-            return editors.length === 0
+            return editorsToClose.length === 0
         },
         {
-            timeout: 5000, // Arbitrary values. Should succeed except when VS Code is lagging heavily.
+            timeout: 1000, // Arbitrary values. Should succeed except when VS Code is lagging heavily.
             interval: 250,
             truthy: true,
         }
     )
 
-    if (!noVisibleEditor) {
-        const editorNames = editors.map((editor) => `\t${editor.document.fileName}`)
+    if (!noVisibleEditor && editorsToClose.length > 0) {
+        const editorNames = editorsToClose.map((editor) => `\t${editor.document.fileName}`)
         throw new Error(`Editors were still open after closeAllEditors():\n${editorNames.join('\n')}`)
     }
 }