Pre-release pipeline: 1ES Network Isolation blocks PyPI on Linux and Windows #26064

Summary

The scheduled pre-release pipeline has been failing across all Linux and Windows packaging jobs because 1ES Network Isolation blocks access to PyPI. This happens before the extension build reaches repository code and is unrelated to the commit at the head of main.

Latest failure:

• GitHub check: https://github.com/microsoft/vscode-python/runs/89951166434

Failure

Every affected job fails at the Install wheel and nox step in build/azure-pipeline.pre-release.yml:

python -m pip install wheel nox

Linux reports:

Failed to establish a new connection: [Errno 1] Operation not permitted
ERROR: Could not find a version that satisfies the requirement wheel (from versions: none)
ERROR: No matching distribution found for wheel

Windows reports:

Failed to establish a new connection: [WinError 10013] An attempt was made to access a socket in a way forbidden by its access permissions
ERROR: Could not find a version that satisfies the requirement wheel (from versions: none)
ERROR: No matching distribution found for wheel

The preceding python -m pip install -U pip step shows the same blocked connection but exits successfully because pip is already installed.

Root cause

The injected 1ES Network Isolation task is running in Enforce mode on Linux and Windows with task version 1.0.162:

NetworkIsolationExe Enforce -UserName cloudtest -Policies Permissive,CFSClean,CFSClean2,CFSClean3