test: migrate to vitest (#34475)

.devcontainer/devcontainer.json

.github/contributing.md

.github/label-actions.yml

.github/workflows/build.yml

.ls-lint.yml

.vscode/extensions.json

.vscode/launch.json

.vscode/settings.json

docs/development/best-practices.md

docs/development/issue-labeling.md

docs/development/local-development.md

eslint.config.mjs

jest.config.ts

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

lib/config/__snapshots__/migrate-validate.spec.ts.snap

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

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

lib/config/index.spec.ts

lib/config/migration.spec.ts

lib/config/migrations/custom/extends-migration.spec.ts