C# 14 post-release tasks

[BillWagner]

Describe the issue or suggestion

Perform the following tasks once .NET 10 / C# 14 has been released:

• Remove <LangVersion>preview</LangVersion> from any pertinent samples
• Remove "preview" language from any C# 14 features.

[cremor]

I assume this sentence will also be removed from the page What's new in C# 14?

New features are added to the "What's new in C#" page when they're available in public preview releases. The working set section of the roslyn feature status page tracks when upcoming features are merged into the main branch.

Also, the very first sentence on the "What's new in C# X" pages for C# 12, 13 and 14 all link to the VS preview/insiders version.