Revisit azure-observability

[kvenkatrajan]

Is it useful?
If so add integration tests and run sensei

[saikoumudi]

I made some changes on this PR -
#1019

However, after testing it, it looks like we may not need this observability skill. Initially, it seemed valuable, but i am unable to repro those scenarios again. I added a check to call @Azure ARG tool but we seem to have a new skill azure-resource-lookup

If it's just for mcp tool mapping, we can delete the skill.

should it call our ARG tool? - https://github.com/microsoft/GitHub-Copilot-for-Azure/blob/main/plugin/skills/azure-resource-lookup/SKILL.md .. touch-based with chris on this and maybe valuable until ARM mcp tools are embedded. may need some more testing.