Fix obsolete X509Certificate2 Errors

[ellahathaway]

Fixes dotnet/source-build#4494

Test build

My local build worked with thes changes, but I'm verifying with the source-build-lite pipeline as well.

[ellahathaway]

It looks like we may have to pull in the latest from runtime in order for this to work at the repo level.

[vcsjones]

👋 This is an interesting case as, currently, there is no replacement API for what you are using X509Certificate2 for. You are likely going to need to suppress the SYSLIB0057 obsoletion as X509CertificateLoader does not handle authenticode inputs.

cc @bartonjs - this is another example of needing to suppress the obsoletion.

[akoeplinger]

See dotnet/docs#41662 (comment) for an example.

We'd need to wrap it in #if NET9_0_OR_GREATER but that still doesn't solve the issue that we don't have a new enough runtime in arcade that contains X509CertificateLoader.

I'd suggest just suppressing SYSLIB0057 for now.

[ellahathaway]

@vcsjones @akoeplinger - Thanks for your help! I appreciate it. I've updated the PR given the guidance

[ellahathaway]

Stage 2 build passed for arcade with these changes. I will have to investigate the arcade-pr failures after I finish with release work.

[bartonjs]

We'd need to wrap it in #if NET9_0_OR_GREATER ...

Or add a package reference to Microsoft.Bcl.Cryptography (the back-compat package)

[ellahathaway]

One of the tests was failing because the filePath did not contain a certificate. This resulted in GetCertContentType() throwing an exception. As a fix, I placed the check for the cert type in the try-catch block.