docs: add release dates to release notes

[prismagod]

Description

Added release dates to the release notes based on Git tags.

Why do we need it, and what problem does it solve?

Release notes did not contain publication dates, which made it harder to track the release timeline.

What is the expected result?

Each release entry now includes its publication date.

Checklist

• The code is covered by unit tests.
• e2e tests passed.
• Documentation updated according to the changes.
• Changes were tested in the Kubernetes cluster manually.

Changelog entries

section: docs
type: docs
summary: "Added release dates to the release notes based on Git tags."
impact_level: low