Subscription test timeout

[paologalligit]

Description

We've had multiple failing tests in ci/cd caused by a timeout while running the subscriptions tests. The issue is not directly reproducible locally and failing runs happen randomly, but the issue seems to be related to the websocket connection not being able to receive a message, so it hangs waiting indefinitely. This PR adds a timeout of 5 seconds: if a message is not received the test is simply skipped.

Fixes issue-199

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] My changes generate no new warnings
• [x] New and existing unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules
• [x] I have not added any vulnerable dependencies to my code