Harden Windows x86-64 CI LLVM install against Chocolatey 504 timeouts

[Copilot]

The Windows x86-64 Actions job failed before compilation in the Install LLVM v14 step due to transient 504 Gateway Timeout responses from Chocolatey. This change makes that dependency install resilient to temporary feed outages without altering the build configuration.

• Root cause addressed

  • choco install llvm --version=14.0.6 --allow-downgrade previously failed fast on a single network timeout.

• Workflow change (.github/workflows/ci.yaml)

  • Replaced the one-shot install command with bounded retry logic in cmd.
  • Retries up to 3 times with a short delay between attempts.
  • Preserves failure behavior if all attempts fail.

• Behavioral impact

  • Improves reliability of the Windows dependency bootstrap path.
  • No changes to compiler version, build flags, packaging, or benchmark/test steps.

set RETRIES=3
set WAIT_SECONDS=20
for /L %%i in (1,1,%RETRIES%) do (
  choco install llvm --version=14.0.6 --allow-downgrade
  if !ERRORLEVEL! EQU 0 goto :success
  if %%i LSS %RETRIES% timeout /t %WAIT_SECONDS% /nobreak >nul
)
exit /b 1
:success

[Copilot]

Pull request overview

This PR improves the resilience of the Windows x86-64 GitHub Actions workflow by adding bounded retry logic around the Chocolatey installation of LLVM 14.0.6, addressing transient Chocolatey feed/network failures (e.g., 504 timeouts) without changing the build/toolchain configuration itself.

Changes:

• Replaced the single choco install llvm --version=14.0.6 --allow-downgrade invocation with a cmd retry loop (3 attempts).
• Added a short wait (timeout) between retries plus clearer log output for attempts and final failure/success.

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[bqminh]

great