Slack classes do not autocomplete in vscode

[ngawor]

Summary

Slack classes do not autocomplete in vscode

Steps To Reproduce:

1. Start typing Sla... no autocomplete.
2. Type Slack... no autocomplete.

Expected result

There should be an autocomplete of the Slack namespace and underlying file-based classes.

Actual result

Autocomplete doesn't work

Additional information

Dev console:

Salesforce Extension Version in VS Code: Salesforce Extension Pack v55.8.0

SFDX CLI Version: sfdx-cli/7.163.0 darwin-x64 node-v16.16.0

OS and version: macOS Monterey 12.5