text: Title: Bug: Linear-Sentry Integration Not Working Despite Successful Activation
  Body: ### Environment
  
  SaaS (https://sentry.io/)
  
  ### Steps to Reproduce
  
  I'll add that important error message to the bug report:
  
  ## Bug: Linear-Sentry Integration Not Working Despite Successful Activation
  
  ### Description
  I successfully activated the Sentry integration through Linear (confirmation received), but I'm unable to create Linear tickets from Sentry. The issue persists across multiple Linear workspaces (both EU and US hosted instances). When attempting to use the integration, an error message appears stating "Unable to connect to Linear."
  
  ### Steps to Reproduce
  1. Initiated the Sentry integration workflow from Linear
  2. Received confirmation of successful integration activation
  3. Attempted to create Linear tickets from Sentry
  4. Observed error message: "Unable to connect to Linear"
  5. Ticket creation fails
  
  ### Environment Details
  - Linear workspaces tested: 2 (one EU-hosted, one US-hosted)
  
  ### Additional Information
  - The integration appears as active in both Linear and Sentry interfaces
  - The error occurs consistently across different Linear workspaces
  
  ![Image](https://github.com/user-attachments/assets/31db09bb-f5df-4c4d-afa8-421b9c220763)
  ![Image](https://github.com/user-attachments/assets/561179a6-4401-4d64-bf9a-e71aa7b7f1ad)
  ![Image](https://github.com/user-attachments/assets/336eb29c-4dd9-44a2-8195-fd618c6d13bb)
  ![Image](https://github.com/user-attachments/assets/bb505d6f-38b4-443b-9558-5c7c7bb8118c)
  ![Image](https://github.com/user-attachments/assets/f30641e9-5e38-42ef-8609-0e7bb75193b5)
  
  ### Expected Result
  
  Should be able to create Linear tickets directly from Sentry after successful integration activation.
  
  ### Actual Result
  
  Unable to create Linear tickets from Sentry despite the integration showing as successfully activated. A specific error message "Unable to connect to Linear" is displayed when attempting to use the integration.
  
  ### Product Area
  
  Settings - Integrations
  
  ### Link
  
  _No response_
  
  ### DSN
  
  _No response_
  
  ### Version
  
  _No response_