ci: store workflow artifacts on self-hosted MinIO (DevinoSolutions/artifact)

[AminDhouib]

Moves every actions/upload-artifact / actions/download-artifact step to
DevinoSolutions/artifact, a drop-in
replacement that stores artifacts on Devino's own MinIO (storage.devino.ca) instead
of GitHub's metered artifact storage.

Why: the org is on the free plan (500 MB artifact quota) with a $0 hard-stop Actions
budget, so once the quota is exceeded every artifact upload is rejected. Self-hosted
runners do not avoid this; the upstream action always writes to GitHub's blob store.

What changed

• uses: lines swapped to DevinoSolutions/artifact/upload@v1 / download@v1; all inputs are compatible.
• Jobs that upload/download now request id-token: write, because the action authenticates to MinIO with the job's GitHub OIDC token (no secrets). Where a job had no permissions block, permissions: write-all is added, which equals the repo's current default token scopes plus id-token.
• retention-days is honoured via bucket lifecycle rules (rounded up to 1/3/5/7/14/30 days; anything above 30 keeps the 90-day default).

Artifacts are listed in each job's step summary as s3://gh-artifacts/<owner>/<repo>/<run_id>/<name>.tgz and can be fetched with mc or browsed at minio-console.devino.ca.