refactor: remove currentVersion (#8708)

lib/config/__snapshots__/migration.spec.ts.snap

lib/config/migration.spec.ts

lib/config/migration.ts

lib/datasource/terraform-module/index.ts

lib/datasource/terraform-provider/index.ts

lib/manager/bazel/update.ts

lib/manager/common.ts

lib/manager/gomod/update.spec.ts

lib/util/template/index.ts

lib/workers/common.ts

lib/workers/repository/updates/flatten.ts

lib/workers/repository/updates/generate.ts