Updating jira cloud broken link in doc/integration/jira/connect-app.md

What does this MR do and why?

Updated jira cloud broken link in doc/integration/jira/connect-app.md as mentioned in #389408 (closed). The existing link https://marketplace.atlassian.com/apps/1221011/gitlab-com-for-jira-cloud has now permanently redirected to https://marketplace.atlassian.com/apps/1221011/gitlab-com-for-jira-cloud?tab=overview&hosting=cloud.

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