Fixup site extensions 3.1 versions

[JunTaoLuo]

This fixes up the version update made in #31773

[ghost]

Hello @dougbu!

Because this pull request has the auto-merge label, I will be glad to assist with helping to merge this pull request once all check-in policies pass.

p.s. you can customize the way I help with merging this pull request, such as holding this pull request until a specific person approves. Simply @mention me (@msftbot) and give me an instruction to get started! Learn more here.

[dougbu]

Set auto-merge to get this in ASAP. But, @wtgodbe and @JunTaoLuo feel free to merge immediately if starting ASP.NET builds is urgent. The PR build won't validate the change. I'm just not sure how pressed for time we are.

[wtgodbe]

This is against main, so no rush

[dougbu]

Oh, I assumed this was against release/5.0. Does this mean we aren't creating up-to-date site extension bundles for 5.0 ❔

We normally do the same thing in that branch though our issue template only mentions "the main copy". IIRC @BrennanConroy suggested doing this in both branches was helpful.

[wtgodbe]

Looks like I missed updating the 5.0 version:

aspnetcore/eng/Versions.props

Line 241 in 415693c

<MicrosoftAspNetCoreAzureAppServicesSiteExtension31PackageVersion>3.1.13-servicing-21117-13</MicrosoftAspNetCoreAzureAppServicesSiteExtension31PackageVersion>

I can create that PR now

[wtgodbe]

#31811

[JunTaoLuo]

Can you also update the doc so we remember to update in both branches?

[wtgodbe]

https://github.com/dotnet/aspnetcore-internal/pull/3809