AI Blurp

This pull request includes changes to the NuGet configuration and build properties to improve package source auditing and manage warnings more effectively. The most important changes are as follows:

NuGet Configuration Updates:

• NuGet.config: Added anauditSources section to specify sources for auditing, includingnuget.org as an audit source.

Build Properties Enhancements:

• src/Directory.Build.props: Introduced aWarningsNotAsErrors property to exclude specific warnings from being treated as errors.
• src/Directory.Build.props: Added aNuGetAuditMode property to enable auditing for all package sources.

Description

Adding new functionality for .NET 9 / VS 17.12 / NuGet 6.12 with Audit Sources.
Also adding that the vulnerabilities (currently) are not treated as errors, but this can of course be enabled in the future

The idea is that package vulnerabilities get visibility at least on a warning level everywhere.
I'm sure I don't have to remind anyone of this, but I still do 😁 :
https://blogs.microsoft.com/blog/2024/05/03/prioritizing-security-above-all-else/

If you’re faced with the tradeoff between security and another priority, your answer is clear: Do security. -- Satya Nadella