GitLab Workflow fails to "validate" valid certificates: Reason: certificate has expired

Checklist

• I'm using the latest version of the extension (see the latest version in the right column of this page)
  • Extension version: Put your extension version here
• I'm using the latest VS Code version (find the latest version here)
  • VS Code version: Put your VS Code version here
• I'm using a supported version of GitLab (see README for the supported version)
  • GitLab version: Put your GitLab version here, or say "happens on gitlab.com"

Summary

I've tried to setup the VSCode GitLab Workflow extension in VSCode with a self-managed instance, which has a valid LetsEncrypt Certificate, which is not expired. If I try to load MR's I get the following error (see logs below): request to https://your.domain/api/graphql failed, reason: certificate has expired.

Steps to reproduce

1. Setup a self-managed GitLab (CE or EE) instance with a reverse proxy using a let's encrypt certificate in front of it (Reverse-Proxy does SSL termination, in my case Traefik)
2. Create a Git-Repository (User Scope)
3. Create a project scoped Personal-Access-Token
4. Install Gitlab Workflow and setup your repository (make sure todo git clone from the upstream repo first)
5. Setup GitLab Workflow with instance url and PAT, try to load data => Bug occurs

What is the current bug behavior?

See Summary

What is the expected correct behavior?

Connection is successful if certificates are valid

Relevant logs and/or screenshots

request to https://your.domain/api/graphql failed, reason: certificate has expired
FetchError: request to https://your.domain/api/graphql failed, reason: certificate has expired
	at ClientRequest.<anonymous> (c:\Users\your-user\.vscode\extensions\gitlab.gitlab-workflow-3.38.2\out\extension.js:253:17119)
	at ClientRequest.emit (events.js:327:22)
	at ClientRequest.EventEmitter.emit (domain.js:467:12)
	at TLSSocket.socketErrorListener (_http_client.js:469:9)
	at TLSSocket.emit (events.js:315:20)
	at TLSSocket.EventEmitter.emit (domain.js:467:12)
	at emitErrorNT (internal/streams/destroy.js:106:8)
	at emitErrorCloseNT (internal/streams/destroy.js:74:3)
	at processTicksAndRejections (internal/process/task_queues.js:80:21)
Found https://your.domain in the PAT list and git remotes, using it as the instanceUrl

Possible fix

No one yet