refactor(datasource/gitlab-tags): Convert to class (#14055)

lib/constants/platform.spec.ts

lib/datasource/api.ts

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

lib/datasource/gitlab-tags/index.ts

lib/datasource/go/base.spec.ts

lib/datasource/go/base.ts

lib/datasource/go/common.ts

lib/datasource/go/index.spec.ts

lib/datasource/go/index.ts

lib/datasource/go/releases-direct.ts

lib/manager/cocoapods/extract.ts

lib/manager/cocoapods/index.ts

lib/manager/gitlabci-include/extract.ts

lib/manager/gitlabci-include/index.ts

lib/manager/pre-commit/extract.ts

lib/manager/pre-commit/index.ts