hotfix: release link into upgrade message

[Eomm]

Creating the tag v3 and v3.0 (ref #112 ) manually by running:

git tag -f 'v3'
git tag -f 'v3.0'
git push origin --tags

This command does not set the tag message that appeared at:

https://github.com/fastify/github-action-merge-dependabot/releases/tag/v3

This PR forces the link to the one created using the GH-UI:

https://github.com/fastify/github-action-merge-dependabot/releases/tag/v3.0.0

Notes

Creating a GH release needs to be verified because the v3 and v3.0 tags will be updated time by time and it may be blocked by GH