eclipse-temurin: update link to slack channel

eclipse-temurin/get-help.md

@@ -1 +1 @@
-[Adoptium Slack](https://adoptium.net/slack.html); [Adoptium Support](https://github.com/adoptium/adoptium-support/issues/new/choose)
+[Adoptium Slack](https://adoptium.net/slack); [Adoptium Support](https://github.com/adoptium/adoptium-support/issues/new/choose)