feat(ci): compose release qualification from targets, flows, and suites #2972

Description

Create a reusable release qualification entry point that consumes an immutable candidate artifact set and composes three independently maintained dimensions:

• targets describe the platform, architecture, runtime, package mechanism, and environment lifecycle;
• flows describe how a release is installed or changed, such as clean install or forward upgrade;
• suites describe the behavior to verify, such as driver conformance.

The qualification matrix must select supported combinations explicitly rather than assume every target, flow, and suite forms a valid Cartesian product.

Context

• Parent release pipeline: feat: 0.1.0 release pipeline #2860
• Reusable release artifacts: chore(ci): clean up release pipeline #1683
• Shared driver conformance suite: spike: driver conformance suite for compute drivers #2183
• Release policy: RFC-0014

The first consumer will be the Fedora rootless Podman proof-of-concept covering clean installation and N to N+1 forward upgrade. Existing release canaries mix environment setup, installation, and assertions in individual workflow jobs, making each new matrix entry expensive to add and difficult to compare.

Definition of Done

• Qualification accepts an immutable candidate artifact manifest containing the release version, source commit, and artifact identities or digests.
• Targets, flows, and suites have separate definitions and lifecycle boundaries.
• Adding a target does not require copying or modifying flow or suite implementations.
• Adding a flow or suite does not require embedding target-specific provisioning logic.
• Supported target, flow, and suite combinations are selected explicitly without generating an unsupported Cartesian product.
• The same qualification entry point can run locally and from GitHub Actions.
• Each selected combination produces a clear pass/fail result plus machine-readable results and retained diagnostics.
• Documentation explains how to add one target, one flow, or one suite independently.