As described in dotnet/source-build-reference-packages#817 (comment), adding SBRP validation tests require reworking the current pipeline.

The proposed change is:

• Job 1: Run build, run tests, and publish for Linux
• Job 2: Run tests on Windows (unable to build and publish for Windows in current stage. Eventually, this job will resemble that of Job 1)
• Job 3: Run SB complete