Add PR verification on Linked Issue

[Daniele Iasella]

As part of the SOC2 compliance, all repositories PRs needs to be linked to an issue.
In order to avoid bigger work during the evidence collection time, a new check needs to be added to block the PR from being merged in case of missing linked issue.

To be investigated:

• https://github.com/marketplace/actions/verify-linked-issue
• https://github.com/nearform-actions/github-action-check-linked-issues