docs: keep 1.6.0 release notes scoped

Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

Author: zeitlinger

AGENTS.md

@@ -94,14 +94,6 @@ Pre-built instrumentations:
 - **Markdown code blocks**: Always specify language
   (e.g., ` ```java`, ` ```bash`, ` ```text`)
 
-## Pull Requests
-
-- PR titles must use semantic/conventional prefixes, for example
-  `feat: ...`, `fix: ...`, `docs: ...`, `chore: ...`, or
-  `test: ...`.
-- Do not prefix PR titles with `[codex]`.
-- Match the PR title type to the primary user-facing change.
-
 ## Linting and Validation
 
 **CRITICAL**: These checks MUST be run before creating any

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [1.6.0](https://github.com/prometheus/client_java/compare/v1.5.1...v1.6.0) (2026-04-25)
 
+> Note: OpenMetrics 2.0 support is still in progress and not ready for general use yet.
+
 ### Features
 
 * Relax metric name validation in Dropwizard5 ([#1985](https://github.com/prometheus/client_java/issues/1985)) ([deb782f](https://github.com/prometheus/client_java/commit/deb782f9fce60ffb1308a98b661c0a1ccb79a82b))