feat(dependabot-2.0): update schema to match current Dependabot features (SchemaStore#5381)

Sync the dependabot-2.0.json schema with the current state of
Dependabot's configuration options, adding missing features and
fixing constraints to match the actual implementation.

Changes:

- Add pre-commit to package-ecosystem enum (beta ecosystem)
  dependabot/dependabot-core#2183

- Add goproxy-server to registry type enum
  https://github.blog/changelog/2025-09-09-go-private-registry-support-for-dependabot-now-generally-available
  dependabot/dependabot-core#12747

- Add OIDC and AWS CodeArtifact registry auth properties
  (tenant-id, client-id, jfrog-oidc-provider-name,
  identity-mapping-name, audience, aws-region, account-id,
  role-name, domain, domain-owner, registry)
  https://github.blog/changelog/2026-02-03-dependabot-now-supports-oidc-authentication

- Add group-by property to groups definition
  https://github.blog/changelog/2024-03-28-dependabot-grouped-security-updates-generally-available

- Add name property to update definition

- Add update-types, dependency-type, and exclude-patterns
  properties to multi-ecosystem-group definition
  https://github.blog/changelog/2025-07-01-single-pull-request-for-dependabot-multi-ecosystem-support

- Fix cooldown constraints to match implementation:
  minimum 1 (not 0) for default/major/minor days,
  maximum 90 for all day fields,
  maxItems 100 (not 150) for include/exclude
  https://github.blog/changelog/2025-07-01-dependabot-supports-configuration-of-a-minimum-package-age

- Fix ignore versions to accept string or array (was array-only)

- Replace inline timezone enum with $ref to base.json

- Add positive tests for new features

Author: JamieMagee