Fix OpenCtx include initial context integeration. (#6045)

Resolves:
https://sourcegraph.slack.com/archives/C07NNEEAU4B/p1730256382790879?thread_ts=1729002871.765829&cid=C07NNEEAU4B

## Background
OpenCtx providers can define `mentions: { autoInclude: true }` to get
called for retrieving initial context items. This was implemented to
support Bridgewater's feature request for Pinned Context.

However, the provider is not getting called for files not inside a git
repo with the remote set. This is because the `codebase` is not
recognized, and we don't call the provider in that case. We recognize
the codebase based on the current working directory and the git remote
set.

This PR solves it by calling the provider even when the codebase is not
resolved.

Demo:
https://www.loom.com/share/1c6724808f164b798f578d7c47481fdf?sid=00219b3a-8691-4d63-8978-d31f50ce6328

## Test plan

Follow the demo

## Changelog

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vscode/src/chat/context/chatContext.ts

@@ -197,7 +197,7 @@ export const activeEditorContextForOpenCtxMentions: Observable<
             return repoNameResolver.getRepoNamesContainingUri(uri).pipe(
                 map(repoNames =>
                     repoNames === pendingOperation
-                        ? pendingOperation
+                        ? { uri: uri.toString(), codebase: undefined }
                         : {
                               uri: uri.toString(),
                               codebase: repoNames.at(0),