fix(amazonq): avoid workspace index process failure

[leigaol]

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Description

Orphaned http request that should be rejected somehow sneaked into the http request event loop while the FAISS index is not ready, causing the workspace LSP process to terminate, which causes the JetBrains IDE to re-initialize the workspace LSP process, which further triggers an infinite loop of log storm that caused slowness (the log loop issue is fixed in #5581).

Here are the sequence of events that happened:

1. JB starts workspace LSP, the LSP then works on tree sitter parsing to generate repomap.
2. When Upgrade Kotlin, IDE, Gradle plugin, fix Toolwindow #1 is in progress, client (user) uses @workspace feature sends a request for vector index query. Upgrade Kotlin, IDE, Gradle plugin, fix Toolwindow #1 is usually fast but for 1.4GB repo like https://github.com/elastic/elasticsearch (1.4GB), it takes 6 min.
3. Node js event loop busy, client request Cred management #2 is timed out. However, requests is cached at server and it becomes an Orphaned http request.
4. The moment when tree sitter parsing is done, node js event loop SOMEHOW immediately handles the Orphaned request in step 2 at a certain possibility!
5. The vector index is not undefined, it was partially initialized, but it had no chunk inside, query when 0 chunks caused Faiss to crash, which terminated the LSP process.
6. JB saw java.net.ConnectException: Connection refused, it then forces LSP to restart, which restarts the indexing, causing performance issue.

Checklist

• My code follows the code style of this project
• I have added tests to cover my changes
• A short description of the change has been added to the CHANGELOG if the change is customer-facing in the IDE.
• I have added metrics for my changes (if required)

License

I confirm that my contribution is made under the terms of the Apache 2.0 license.