refactor: convert ProgrammingLanguage to union type (#18748)

lib/constants/programming-language.ts

lib/modules/manager/ansible/index.ts

lib/modules/manager/bundler/index.ts

lib/modules/manager/cake/index.ts

lib/modules/manager/cargo/index.ts

lib/modules/manager/composer/index.ts

lib/modules/manager/docker-compose/index.ts

lib/modules/manager/dockerfile/index.ts

lib/modules/manager/droneci/index.ts

lib/modules/manager/gitlabci/index.ts

lib/modules/manager/gomod/index.ts

lib/modules/manager/gradle/index.ts

lib/modules/manager/index.ts

lib/modules/manager/kubernetes/index.ts

lib/modules/manager/maven/index.ts

lib/modules/manager/meteor/index.ts

lib/modules/manager/mix/index.ts

lib/modules/manager/nodenv/index.ts

lib/modules/manager/npm/index.ts

lib/modules/manager/nuget/index.ts