test: Use nock for tests (Part 2) (#6519)

lib/datasource/crate/__snapshots__/index.spec.ts.snap

lib/datasource/crate/index.spec.ts

lib/datasource/dart/__snapshots__/index.spec.ts.snap

lib/datasource/dart/index.spec.ts

lib/datasource/docker/index.spec.ts

lib/datasource/galaxy/index.spec.ts

lib/datasource/gitlab-tags/index.spec.ts

lib/datasource/helm/__snapshots__/index.spec.ts.snap

lib/datasource/helm/index.spec.ts

lib/datasource/hex/__snapshots__/index.spec.ts.snap

lib/datasource/hex/index.spec.ts

lib/datasource/npm/__snapshots__/get.spec.ts.snap

lib/datasource/npm/get.spec.ts

lib/datasource/npm/get.ts

lib/datasource/nuget/__snapshots__/index.spec.ts.snap

lib/datasource/nuget/index.spec.ts

lib/datasource/orb/__snapshots__/index.spec.ts.snap

lib/datasource/orb/index.spec.ts

lib/datasource/packagist/__snapshots__/index.spec.ts.snap

lib/datasource/packagist/index.spec.ts