Switch openSUSE 16.0 helix image to use microsoft-opensuse15-testing-prod feed for libmsquic

[Copilot]

The openSUSE 16.0 helix image build was failing due to libmsquic dependency conflicts. The production feed package requires libcrypto.so.1.1, which is incompatible with openSUSE Leap 16.0.

Changes

• Package feed: Switched from packages.microsoft.com/opensuse/15/prod to packages.microsoft.com/yumrepos/microsoft-opensuse15-testing-prod
• Version: Updated libmsquic from 2.4.8 to 2.4.17~rc2 (testing feed has RC versions only, depends on libcrypto.so.3)
• Documentation: Added comments explaining feed choice and RC version necessity

# Using RC version from testing feed as it has correct dependencies (libcrypto.so.3)
# The production feed versions depend on libcrypto.so.1.1 which is incompatible
ARG LIBMSQUIC_VERSION=2.4.17~rc2

# Install MsQuic from official GitHub releases
# Using opensuse15 testing feed as it's compatible with openSUSE 16.0
# See: https://github.com/microsoft/msquic/issues/5567#issuecomment-3618761370
RUN wget https://packages.microsoft.com/keys/microsoft.asc \
    && rpm --import microsoft.asc \
    && rm microsoft.asc \
    && wget "https://packages.microsoft.com/yumrepos/microsoft-opensuse15-testing-prod/Packages/l/libmsquic-${LIBMSQUIC_VERSION}-1.x86_64.rpm" \
    && rpm -i libmsquic-${LIBMSQUIC_VERSION}-1.x86_64.rpm \
    && rm libmsquic-${LIBMSQUIC_VERSION}-1.x86_64.rpm

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.