docs: update End-of-Life-Strategy.md with ubuntu-26.04 CI/CD runner info

Co-authored-by: pethers <1726836+pethers@users.noreply.github.com>

Author: Copilot

End-of-Life-Strategy.md

@@ -53,6 +53,7 @@ See [README.md - Deployment Options](README.md#deployment-options) for deploymen
 - **Current Runtime**: Java 26 GA (Temurin) — production runtime as of April 2026
 - **Source Compatibility**: Java 21 LTS — source compilation level maintained for stability and broad library compatibility
 - **Build Tool**: Maven 3.9.16
+- **CI/CD Runner**: Ubuntu 26.04 — GitHub Actions runner OS as of June 2026
 - **JVM Monitoring**: Regularly evaluate compatibility with new JVM versions.
 - **EOL Trigger**: The project will officially end when updates require Jakarta namespaces for continued compatibility.