Avoid Windows integration cache upload failures on 6.53.x

[AliDatadog]

What

Windows MSI package builds on 6.53.x fail whenever an integration wheel is missing from the dd-agent-omnibus cache. The Windows runner role can read the public cache but cannot upload a newly built wheel, and the existing cache-upload command treats S3 AccessDenied as a fatal package-build error.

This change passes the existing INTEGRATION_WHEELS_SKIP_CACHE_UPLOAD=true guard into the Windows MSI build container. Cache reads remain enabled, cache misses are still built and installed locally, and only the optional upload is skipped.

Why

Both Windows packaging jobs in PR #53401 reproduced the same failure for expired active_directory cache entries:

• Python 3: job 1873918485
• Python 2: job 1873956115

In both cases, the integration wheel built successfully and the job failed only when dd-runner-windows-profile attempted s3:PutObject. Retrying cannot repair the cache because every observed Windows MSI runner uses the same unauthorized role.

Validation

• git diff --check
• YAML parse with yq
• dda inv lint-gitlab passed all four preset contexts using a project-scoped token
• Pre-commit hooks passed
• Signed commit verified locally
• Skeptical review confirmed the variable is scoped to the MSI base shared by both failing jobs and that the existing Ruby guards preserve cache reads/build/install

CI must exercise an MSI cache miss to prove the upload path is skipped; a cache-hit-only run is insufficient.