Remove redundant model-namespace: false from azure-typespec/http-client-csharp emitter configurations

[Copilot]

Summary

Removes redundant model-namespace: false settings from @azure-typespec/http-client-csharp emitter configurations across TypeSpec projects. Since the default value for model-namespace is already false, explicitly setting this value is unnecessary.

Changes Made

• Removed model-namespace: false lines from @azure-typespec/http-client-csharp emitter configurations in 34 TypeSpec configuration files
• Preserved all other configuration options and maintained YAML structure integrity
• No functional changes - behavior remains identical since we're removing redundant explicit defaults

Files Updated

Updated tspconfig.yaml files across various Azure service specifications:

• AI services (OpenAI, Cognitive Services, etc.)
• Communication services (Messages, JobRouter)
• Event Grid services
• Azure Batch
• Load Testing
• And 24 other TypeSpec projects

Validation

• ✅ Verified YAML syntax remains valid in all modified files
• ✅ Confirmed TypeSpec compilation works correctly after changes
• ✅ Validated that no model-namespace: false instances remain in @azure-typespec/http-client-csharp emitter configurations

Example of change made:

  "@azure-typespec/http-client-csharp":
    namespace: Azure.Communication.Messages
-   model-namespace: false

Fixes #35763.

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[openapi-pipeline-app]

Next Steps to Merge

Next steps that must be taken to merge this PR:

• ❌ This PR is labelled with ArcReview. For this PR to be merged, it must pass an ARC review and be labelled ArcSignedOff.
  Email the ARC board to request review per this Contact section.
• ❌ The required check named Automated merging requirements met has failed. This is the final check that must pass. Refer to the check in the PR's 'Checks' tab for details on how to fix it and consult the aka.ms/ci-fix guide. In addition, refer to step 4 in the PR workflow diagram

[openapi-pipeline-app]

PR validation pipeline restarted successfully. If there is ApiView generated, it will be updated in this comment.