Drop 1.19 from version drop-down due to OTel issues & warn folks on the blog (#6348)

* Drop 1.19 from version drop-down due to OTel issues & warn folks on the blog

* Update blog/docs/releases/announcing-knative-v1-19-release.md

Co-authored-by: Calum Murray <[email protected]>

---------

Co-authored-by: Calum Murray <[email protected]>

Author: dprotaso

blog/docs/releases/announcing-knative-v1-19-release.md

@@ -10,6 +10,9 @@ type: "blog"
 
 ## Announcing Knative v1.19 Release
 
+!!! note
+    We've discovered severe issues with the OpenTelemetry Prometheus Exporter (see: https://github.com/knative/pkg/issues/3224). We advise users to hold off upgrading until we have new patch releases out.
+
 A new version of Knative is now available across multiple components.
 
 Follow the instructions in

hack/build.sh

@@ -27,7 +27,7 @@ set -x
 # 1) Make a release-NN branch as normal.
 # 2) Update VERSIONS below (on main) to include the new version, and remove the oldest
 #    Order matters :-), Most recent first.
-VERSIONS=("1.19" "1.18" "1.17") # Docs version, results in the url e.g. knative.dev/docs-1.9/..
+VERSIONS=("1.18" "1.17") # Docs version, results in the url e.g. knative.dev/docs-1.9/..
 # 4) PR the result to main.
 # 5) Party.