ci: refresh TypeScript reference seller pin

[bokelley]

Summary

• updates the release interop TypeScript reference seller pin from the stale beta.12 commit to the known-good beta.17 release commit
• updates the workflow summary note to match the new pin

Root cause

The TypeScript seller in current main already passes the rc4 storyboard. The release warning came from the workflow matrix checking out an older pinned TypeScript reference seller commit that still fails two media-buy storyboard assertions under the current SDK runner.

Validation

• ADCP_SKIP_NPM_CI=1 ADCP_SKIP_BUILD=1 ./scripts/ci/run_storyboard_reference_seller.sh
• npm run lint:workflows
• git diff --check
• npx commitlint --from origin/main --to HEAD --verbose
• pre-push typecheck/build

[aao-ipr-bot]

LGTM. Workflow-only pin refresh, both call sites moved in lockstep.

Things I checked

• Pinned commit df7b5837 exists on main and corresponds to @adcp/sdk@8.1.0-beta.17 (verified package.json at that SHA).
• Both occurrences updated: matrix row at .github/workflows/interop-python.yml:111 and the summary note at :280. No stale beta.12 reference left in the workflow.
• No src/lib/, bin/, scripts/, or published-files surface touched — no changeset required.
• Validation block in the PR body covers the storyboard harness, workflow lint, and commitlint.

Safe to merge.