Add Cobalt Azure Linux 3 CI runs

[LoopedBard3]

Added Cobalt Azure Linux 3 CI runs. This includes adding the cobalt-cloud-lin-al3 azure profile for running the jobs, creating a new yml for a new pipeline for the cobalt network job queue, and moving the previously added cobalt jobs to the new pipeline. Also made a minor update to the core counts for the profiles to match the actual available cores on the cobalt VMs.

The reason for the addition of a new Azure CI pipeline is that the Cobalt machines were made in Azure East US 2 while the other azure machines were in a different region and VNet. As such, the service bus queue management machines are not able to send jobs between the two networks. The two options to work around this I came up with were to either have a new pipeline for each network we need to send runs to (which I don't think we will have many of) o,r update the liquid templates queue selection setup to include different queue lists per network and specifying the network on a per job level. I think adding the pipeline is the cleaner of these two options, at least at this moment, and keeps wider updates from being necessary.

[Copilot]

Pull Request Overview

This PR splits the existing Azure CI runs into a new East US 2 pipeline for Cobalt machines, updates VM core counts to 16, and adds a new AL3 profile:

• Remove all cobalt-cloud-lin jobs from the main Azure pipelines and move them into a dedicated East US 2 pipeline
• Introduce a new cobalt-cloud-lin-al3 profile (and related relay) and update core counts from 4 to 16
• Add benchmarks.matrix.azure.eastus2.yml and benchmarks-ci-azure-eastus2.yml for the Cobalt East US 2 runs

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
build/benchmarks.matrix.azure.yml	Removed cobaltcloud queue and all Cobalt job entries
build/benchmarks.matrix.azure.eastus2.yml	Added matrix definitions for Cobalt (AL2 and AL3) in East US 2
build/benchmarks-ci-azure.yml	Removed all Cobalt Cloud Linux jobs and updated dependsOn arrays
build/benchmarks-ci-azure-eastus2.yml	New CI pipeline file for Cobalt East US 2 jobs (AL2 and AL3)
build/azure.profile.yml	Increased core counts to 16 and added cobalt-cloud-lin-al3/relay profiles

Comments suppressed due to low confidence (3)

build/benchmarks-ci-azure.yml:62

• [nitpick] Since the Cobalt Cloud Linux jobs have been removed, consider renumbering this comment from # GROUP 2 to # GROUP 1 and updating subsequent group labels to keep section numbering consistent.

# GROUP 2 

build/benchmarks.matrix.azure.eastus2.yml:1

• [nitpick] Add or update project README or CI documentation to reference this new Azure East US 2 matrix file so contributors are aware of the separate pipeline setup for Cobalt machines.

# This file describes all the scenarios which are run continuously on AzDo. 

build/azure.profile.yml:379

• The cobalt-cloud-lin-al3-relay profile is added but not used in any of the new CI pipelines; consider removing it if unnecessary or including it where appropriate to avoid orphaned configuration.

cobalt-cloud-lin-al3-relay: