Fix up devdiv pool usage in official arcade templates

[riarenas]

• This issue is blocking
• This issue is causing unreasonable pain

There is at least one instance of the official Arcade templates where we are using the incorrect pool and image combination: https://github.com/dotnet/arcade/blob/release/6.0/eng/common/templates-official/post-build/post-build.yml#L139-L141

We should go through the templates to make sure we're consistent in our choice of pool + image in devdiv.

[dougbu]

@riarenas, could you please remove use of the -pt images while updating any other dotnet/arcade branch w/ this issue❔

[riarenas]

I think that will make the changes larger than I want to target them. I'll scope this issue just to fixing real blocking issues with using non-compatible images.

[dougbu]

well, 😦 I'll create another issue in this repo for -pt usage cleanup

[riarenas]

6.0: #14654

[riarenas]

I think it was good to create the other issue, I could only find the instances in #14654 for this issue. I'll work on #14652 next.

[dougbu]

I'll work on #14652 next.

that one doesn't feel urgent to me. but if you have time 😁

[riarenas]

I could only find two instances of broken pools. So I think this issue is done.