Revise AI Integration section in SKILL.md

[kzu]

Updated AI integration section to reflect new libraries and practices.

Description

Time to drop SK now that MS.A.AI is RC2

Type of Contribution

• Update to existing instruction, prompt, agent, plugin, skill, or workflow.

[Copilot]

Pull request overview

Updates the .NET best-practices skill’s AI guidance to reflect a move away from Semantic Kernel toward newer Microsoft AI libraries.

Changes:

• Renames the “Semantic Kernel & AI Integration” section to “AI Integration”.
• Replaces Semantic Kernel guidance with Microsoft.Extensions.AI + Microsoft.Agents.AI.
• Simplifies wording around configuration/service registration.

[Copilot]

There is another copy of this skill at plugins/csharp-dotnet-development/skills/dotnet-best-practices/SKILL.md that still references Semantic Kernel. If the intent is to move away from Semantic Kernel, this change should be mirrored there as well (or the plugin copy should be removed/explicitly documented as intentionally different) to avoid conflicting guidance.

Suggested change

	- Use Microsoft.Extensions.AI and Microsoft.Agents.AI for AI operations
	- Implement proper configuration and service registration
	- Use Microsoft.Extensions.AI and Microsoft.Agents.AI for AI operations (this skill is intended for the non–Semantic Kernel stack)
	- Implement proper configuration and service registration for these AI services

[Copilot]

The PR description suggests "drop SK" broadly, but this PR only updates this one SKILL.md and leaves other Semantic Kernel guidance in-repo (e.g., agents/semantic-kernel-*.agent.md and the plugin copy of this skill). Either narrow the PR description/scope, or include the additional updates needed to match the stated intent.

[aaronpowell]

PR's should target the staged branch and not contain file addons to the plugin folder.