Remove -pt images

[dougbu]

The -pt build images are now 100% redundant. As soon as telemetry (below) indicates it's safe, we should remove these images. Preparation includes notifying (well, reminding) our customers that the removal is coming and removing use in dotnet/arcade branches. For the second, see dotnet/arcade#14652.

Check for recent -pt image uses in engsrvprod/engineeringdata is

TimelineRecords
| where FinishTime > ago(7d) and ImageName matches regex '1es-.*-pt'
| distinct ImageName

Release Note Category

• Feature changes/additions
• Bug fixes
• Internal Infrastructure Improvements

Release Note Description

Removed the now-redundant 1es-*-pt build images from our pools.

[dougbu]

Fixed in !38940

[dougbu]

done