Chat/Edit: Fix symbol hint label typo (#2711)

## Description

Fixes typo to use correct ellipsis 

## Test plan

Copy change, check UI is correct

<!-- Required. See
https://sourcegraph.com/docs/dev/background-information/testing_principles.
-->

vscode/src/non-stop/FixupTypingUI.ts

@@ -55,7 +55,7 @@ const MATCHING_CONTEXT_FILE_REGEX = /@(\S+)$/
 const MATCHING_SYMBOL_REGEX = /@#(\S+)$/
 
 const MAX_FUZZY_RESULTS = 20
-const FILE_HELP_LABEL = 'Search for a file to include, or type # to search symbols..'
+const FILE_HELP_LABEL = 'Search for a file to include, or type # to search symbols...'
 const SYMBOL_HELP_LABEL = 'Search for a symbol to include...'
 const NO_MATCHES_LABEL = 'No matches found'
 

vscode/test/e2e/at-file-context-selecting.test.ts

@@ -17,7 +17,7 @@ test('@-file empty state', async ({ page, sidebar }) => {
     const chatInput = chatPanelFrame.getByRole('textbox', { name: 'Chat message' })
     await chatInput.fill('@')
     await expect(
-        chatPanelFrame.getByRole('heading', { name: 'Search for a file to include, or type # to search symbols..' })
+        chatPanelFrame.getByRole('heading', { name: 'Search for a file to include, or type # to search symbols...' })
     ).toBeVisible()
 
     // No results

vscode/webviews/UserContextSelector.tsx

@@ -34,7 +34,7 @@ export const UserContextSelectorComponent: React.FunctionComponent<
 
     let headingTitle
     if (formInput.endsWith('@')) {
-        headingTitle = 'Search for a file to include, or type # to search symbols..'
+        headingTitle = 'Search for a file to include, or type # to search symbols...'
     } else if (formInput.endsWith('@#')) {
         headingTitle = 'Search for a symbol to include...'
     } else if (formInput.match(/@[^ #]+$/)) {