Remove SLES 12 queues from Helix

[ilyas1974]

Based on the official .NET support matrix (https://github.com/dotnet/core/tree/main/release-notes) and usage data in Kusto, the SLES 12 queues have not been used within the last 90 days. Please remove them from Helix.

Queues in question:

• Internal - sles.12.amd.64 and sles.12.amd64.svc
• Public - sles.12.amd64.open, sles.12.amd64.open.rt, and sles.12.amd64.open.svc

Release Note Category

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

Release Note Description

Remove sles 12 queues from Helix

[ilyas1974]

Assigning this a P1 priority as I believe having these queues around has cause some issues with python updates, we've been trying to do
/cc: @dougbu

[dougbu]

putting up a real quick PR for this since it's near and dear to my heart ❤