[Wiktor Kopec (wiktork)]

Summary

Fix the Linux CI failures in run 2026101601 by authenticating to the build-image registry before 1ES network isolation starts. The existing Docker Login user step ran after isolation blocked registry access, preventing all four Linux builds from starting.

Change Log

• Configure templateContext.authenticatedContainerRegistries for 1ES Linux binary jobs so the supported template hook authenticates before network isolation.
• Declare the Linux steps template's OneESPT parameter and retain the explicit Azure CLI login only for non-1ES pipelines, avoiding duplicate authentication.
• Document the authentication ordering requirement. Network isolation and existing build behavior remain unchanged.

Test Methodology

• Passed: ClrInstrumentationEngine-CI-Yaml run 2026102201 completed with result Succeeded on branch wiktork/fix-linux-ci-acr-auth, commit e92e644f217223682caec7f9f981c6880db334ad. This exercises Linux and Windows builds, tests, and packaging.
• Passed: git diff --check origin/main...HEAD.
• Passed: the following command parsed all 51 pipeline YAML files:

  python -c "import pathlib, yaml; files = list(pathlib.Path('build/yaml').rglob('*.yaml')); [yaml.safe_load(p.read_text(encoding='utf-8-sig')) for p in files]; print(f'Parsed {len(files)} pipeline YAML files successfully')"

• No local compilation was run for this pipeline-only change; compilation and tests were performed by the successful CI run.