Sync eng/common directory with azure-sdk-tools for PR 15357

[azure-sdk]

Sync eng/common directory with azure-sdk-tools for PR Azure/azure-sdk-tools#15357 See eng/common workflow

[Copilot]

Pull request overview

Syncs eng/common pipeline templates with the corresponding updates from azure-sdk-tools PR 15357, primarily around GitHub authentication/token handling in pipeline jobs.

Changes:

• Added login-to-github.yml usage to mint GitHub App installation tokens in pipeline jobs.
• Switched GitHub auth inputs from $(azuresdk-github-pat) to $(GH_TOKEN) / $(GH_TOKEN_Azure) in the updated flows.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
eng/common/pipelines/templates/jobs/prepare-pipelines.yml	Adds GitHub login step for *-pr repos and updates sparse-checkout auth to use $(GH_TOKEN).
eng/common/pipelines/templates/archetype-typespec-emitter.yml	Adds GitHub login steps to regeneration jobs and updates PR submission auth token usage.

[Copilot]

login-to-github.yml runs before sparse-checkout.yml, but login-to-github.yml executes eng/common/scripts/login-to-github.ps1 via scriptPath. In this job, the only checkout currently comes from sparse-checkout.yml (which also does checkout: none by default), so the repo files containing eng/common/scripts/ are not guaranteed to exist yet when the login step runs. This is likely to fail with a missing script path. Consider either (a) ensuring the repo containing eng/common/scripts/login-to-github.ps1 is checked out before this step, or (b) restructuring so the login step can run after a checkout that includes /eng/common/scripts (and adjusting how the auth token is provided to the subsequent sparse checkout).

Suggested change

	- ${{ if endsWith(parameters.Repository, '-pr') }}:
	- ${{ if endsWith(parameters.Repository, '-pr') }}:
	- checkout: self