Upgrade Azure generator TypeSpec dependencies to 1.9.0#56295

Copilot wants to merge 2 commits intotypespec/update-http-client-1.0.0-alpha.20260214.2Azure/azure-sdk-for-net:typespec/update-http-client-1.0.0-alpha.20260214.2from

copilot/sub-pr-56294Azure/azure-sdk-for-net:copilot/sub-pr-56294Copy head branch name to clipboard