Update package references to use version wildcards for named-pipe agent

[matthewmeyer]

This pull request updates the dependencies for both the .NET and Node.js named pipe agent samples to use the latest stable 1.6.x versions, removing explicit references to beta packages and cleaning up unused or unnecessary dependencies in the Node.js sample. This helps ensure better stability, maintainability, and compatibility with the latest package releases.

Dependency updates and cleanup:

.NET sample:

• Updated Microsoft.Agents.Hosting.AspNetCore and Microsoft.Agents.Hosting.DirectLine.NamedPipes package references in NamedPipeAgent.csproj from a specific beta version to the latest 1.6.x stable version.

Node.js sample:

• Updated @microsoft/agents-hosting and @microsoft/agents-hosting-directline-namedpipes dependencies in both package.json and package-lock.json from a specific beta version to the latest 1.6.x stable version. [1] [2]
• Upgraded related dependencies (@microsoft/agents-activity, @microsoft/agents-telemetry) to stable 1.6.1 releases in package-lock.json. [1] [2]
• Upgraded the @types/node dev dependency to a newer patch version.
• Removed several unused or unnecessary dependencies from package-lock.json, such as axios, object-path, and their transitive dependencies, streamlining the dependency tree. [1] [2] [3] [4]