chore!: remove unused oauth setting (#31102)

.changeset/large-clouds-talk.md

apps/meteor/app/api/server/v1/settings.ts

apps/meteor/app/apple/server/appleOauthRegisterService.ts

apps/meteor/app/dolphin/server/lib.ts

apps/meteor/app/lib/server/methods/removeOAuthService.ts

apps/meteor/app/meteor-accounts-saml/server/lib/settings.ts

apps/meteor/definition/externals/service-configuration.d.ts

apps/meteor/server/lib/cas/updateCasService.ts

apps/meteor/server/lib/oauth/addOAuthService.ts

apps/meteor/server/lib/oauth/initCustomOAuthServices.ts

apps/meteor/server/lib/oauth/updateOAuthServices.ts

apps/meteor/server/settings/cas.ts

apps/meteor/server/settings/oauth.ts

apps/meteor/server/startup/migrations/index.ts

apps/meteor/server/startup/migrations/v314.ts

packages/core-typings/src/ILoginServiceConfiguration.ts

packages/i18n/src/locales/af.i18n.json

packages/i18n/src/locales/ar.i18n.json

packages/i18n/src/locales/az.i18n.json

packages/i18n/src/locales/be-BY.i18n.json