docs: update release notes with OLM warning

[razvan]

Release Notes for SDP YY.M.X

Caution

Please assign the applicable scheduled-for/YY.M.X label.

Tip

• Use the commented out template headings in release-notes.
• Begin each sentence on a new line. This helps with review suggestions and diffing.
• Use xrefs for links to other parts of the documentation so that they remain valid across versions.

Release note compilation tasks

• Check Issues for Product and Platform release notes
• Check PRs for Product and Platform release notes
• Optionally check the Changelogs in case release notes were missed
• Compile list of new product versions that are supported and compile a list of new product features to include in the Release Highlights
• Upgrade guide: Document how to use stackablectl to uninstall all and install new release
• Upgrade guide: Document how to use helm to uninstall all and install new release
• Upgrade guide: Every breaking change of all our operators
• Upgrade guide: List removed product versions (if there are any)
• Upgrade guide: List removed operators (if there are any)
• Upgrade guide: List supported Kubernetes versions

Each of the following tasks focuses on a specific goal and should be done once the items above have been completed.

Release note review tasks

• Check overall document structure
• Check spelling, grammar, and correct wording
• Check that internal links are xrefs
• Check that rendered links are valid
• Check that each sentence begins on a new line