refactor: narrow datasource config types

lib/datasource/ansible-galaxy/index.ts

lib/datasource/cargo/index.ts

lib/datasource/cdnjs/index.ts

lib/datasource/common.ts

lib/datasource/dart/index.ts

lib/datasource/docker/index.ts

lib/datasource/git-submodules/index.ts

lib/datasource/git-tags/index.ts

lib/datasource/github-releases/index.ts

lib/datasource/github-tags/index.ts

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

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

lib/datasource/gitlab-tags/index.ts

lib/datasource/go/index.ts

lib/datasource/gradle-version/index.ts

lib/datasource/helm/index.ts

lib/datasource/hex/index.ts

lib/datasource/maven/index.ts

lib/datasource/npm/releases.ts

lib/datasource/nuget/index.ts