Release notes cleanup 2.51.0.

[RohitRanjanMS]

Issue describing the changes in this PR

Updating release docs.

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes should not be added to the release notes for the next release
  • Otherwise: I've added my notes to release_notes.md
• My changes do not need to be backported to a previous version
  • Otherwise: Backport tracked by issue/PR #issue_or_pr
• I have added all required tests (Unit tests, E2E tests)

Additional information

Additional PR information

[Copilot]

Pull Request Overview

This PR cleans up release notes after the 2.51.0 release by replacing specific version numbers and release entries with template placeholders, preparing the documentation for future releases.

• Replaces version numbers (2.51.0, 1.1.0) with <version> placeholder
• Replaces specific release note entries with <entry> placeholder
• Maintains consistent release notes structure across multiple packages

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/DotNetWorker.OpenTelemetry/release_notes.md	Resets OpenTelemetry package release notes to template format
release_notes.md	Resets main release notes for Worker metapackage, Core, and Grpc packages to template format

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.