ci-copilot: set pipeline run title early using build.updatebuildnumber

[Copilot]

Pipeline runs for the Copilot CI pipeline had no meaningful title, making it hard to identify runs at a glance. This adds a step immediately after Validate Parameters that renames the run to PR: {PRNumber} {Platform} using the Azure DevOps logging command.

Change

• eng/pipelines/ci-copilot.yml: Adds a Set Pipeline Run Title step after Validate Parameters:

- script: |
    echo "##vso[build.updatebuildnumber]PR: ${{ parameters.PRNumber }} ${{ parameters.Platform }}"
  displayName: 'Set Pipeline Run Title'

Produces titles like PR: 1234 android or PR: 5678 ios. Implemented as a bash script: for compatibility with the macOS agents used by this pipeline.

Original prompt

Create a pull request in dotnet/maui (base branch copilot-ci) to update the Azure DevOps pipeline at eng/pipelines/ci-copilot.yml so that the pipeline run title/build number is updated early in the run.

Requirements:

• Add a step shortly after the existing Validate Parameters step to rename the pipeline run using Azure DevOps logging command ##vso[build.updatebuildnumber]....
• The run title should be exactly: PR: {PR number} {Platform} where:
  • PR number comes from parameter ${{ parameters.PRNumber }}
  • Platform comes from parameter ${{ parameters.Platform }}
• Use a clear displayName, e.g. Set Pipeline Run Title.
• Keep the change minimal and do not alter existing behavior beyond setting the run title.

Context:

• File source URL: https://github.com/dotnet/maui/blob/copilot-ci/eng/pipelines/ci-copilot.yml
• CommitOID (context): 4896e12

Notes:

• Implement as a YAML step using script: (bash) for maximum compatibility on macOS agents.
• Ensure the title format does not include parentheses—use a single space between PR number and platform, e.g. PR: 1234 android.

This pull request was created from Copilot chat.

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