Shift Linux OpenSSL CI Coverage to Ubuntu 26.04

[Santhosha-bk]

Description

Updated the GitHub pipelines to generate MsQuic binaries that dynamically link OpenSSL libcrypto and libssl, by shifting Linux OpenSSL build and test coverage to Ubuntu 26.04.

#6092

Testing

Documentation

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.54%. Comparing base (b3ba24c) to head (b55b124).
⚠️ Report is 11 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6155      +/-   ##
==========================================
+ Coverage   84.49%   85.54%   +1.04%     
==========================================
  Files          60       60              
  Lines       18973    18974       +1     
==========================================
+ Hits        16031    16231     +200     
+ Misses       2942     2743     -199     

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[Copilot]

Pull request overview

This PR updates the Linux CI configuration to introduce Ubuntu 26.04 as a build/test target and adds a corresponding cross-compile Docker image definition, aligning Linux OpenSSL coverage with Ubuntu 26.04 to support dynamically linking against system libcrypto/libssl.

Changes:

• Add ubuntu-26.04 to Linux build/test matrices (including OpenSSL + -UseSystemOpenSSLCrypto coverage).
• Extend the cross-compile Docker publishing workflow to build the Ubuntu 26.04 image.
• Introduce a new .docker/ubuntu-26.04 Dockerfile for the CI container environment.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
.github/workflows/test.yml	Adds Ubuntu 26.04 entries to build/test vectors for Linux.
.github/workflows/docker-publish-xcomp.yml	Publishes cross-compile container images for Ubuntu 26.04.
.github/workflows/build.yml	Adds Ubuntu 26.04 to the build matrix (impacts Linux + Android dimensions).
.github/workflows/build-reuse-unix.yml	Documents Ubuntu 26.04 as a valid os input.
.docker/ubuntu-26.04/Dockerfile	New Ubuntu 26.04 container image for CI builds/cross-build dependencies.

Comments suppressed due to low confidence (1)

.github/workflows/build.yml:132

• Adding ubuntu-26.04 to the OS matrix makes -UseIoUring combinations run on ubuntu-26.04 too, but the workflow comment/excludes indicate io_uring is intended to be tested only on x64 ubuntu-24.04. Without an explicit exclusion, CI will schedule io_uring builds on 26.04 as well.

        systemcrypto: ['', '-UseSystemOpenSSLCrypto']
        static: ['', '-Static']
        clang: ['', '-Clang']
        codecheck: ['', '-CodeCheck']
        iouring: ['', '-UseIoUring']