[Doc] 3.4.1 RelNotes

[catalinaadam]

PMM-0

Link to the Feature Build: SUBMODULES-0

If this PR adds or removes or alters one or more API endpoints, please review and add or update the relevant API documents as well:

• API Docs updated

If this PR is related to some other PRs in this or other repositories, please provide links to those PRs:

• Links to related pull requests (optional).

[Copilot]

Pull Request Overview

This PR adds release notes for PMM 3.4.1, documenting security fixes and vulnerability assessments for the maintenance release dated October 8th, 2025.

• Adds comprehensive release notes covering security vulnerabilities and their resolutions
• Documents fixes for DoS vulnerabilities in Nomad and Percona Toolkit
• Details vulnerability assessments showing PMM is not affected by certain CVEs

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[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

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[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

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[aaron-percona]

LGTM.