chore(renovate): migrate from dependabot

[swernerx]

Summary

• remove the legacy Dependabot configuration
• add a minimal Renovate config extending the shared Sebastian Software preset

Notes

• dependency update behavior is controlled centrally by sebastian-software/renovate-config
• this PR intentionally does not update dependencies

[greptile-apps]

Greptile Summary

This PR migrates dependency update management from Dependabot to Renovate by deleting the existing .github/dependabot.yml and adding a minimal renovate.json that delegates all configuration to the shared sebastian-software/renovate-config preset.

• The old Dependabot config had open-pull-requests-limit: 0 for both npm and github-actions ecosystems, meaning it was effectively disabled (no PRs were being opened). The migration to Renovate enables centralized control of update behavior via the shared preset.
• The new renovate.json is intentionally minimal — it simply extends the org-level preset so update policy is managed centrally rather than per-repo.

Confidence Score: 5/5

Safe to merge — this is a pure config migration with no code or dependency changes.

Both changed files are tooling config only. The removed Dependabot config was already inert (both ecosystems had open-pull-requests-limit: 0), and the new Renovate config correctly extends the org-level shared preset with a valid schema reference. There is nothing here that could affect the plugin's runtime behavior.

No files require special attention.

Important Files Changed

Filename	Overview
.github/dependabot.yml	Deleted Dependabot config that had open-pull-requests-limit: 0 for both ecosystems (effectively disabled). Safe to remove.
renovate.json	New minimal Renovate config extending the org-level shared preset; valid schema reference and standard pattern for centralized config.

_{Reviews (1): Last reviewed commit: "chore(renovate): migrate from dependabot" | Re-trigger Greptile}