test: Fix test descriptions and enforce it via new linting rule (#11285)

.eslintrc.js

lib/config/decrypt.spec.ts

lib/config/index.spec.ts

lib/config/massage.spec.ts

lib/config/migrate-validate.spec.ts

lib/config/migration.spec.ts

lib/config/options/index.spec.ts

lib/config/presets/azure/index.spec.ts

lib/config/presets/bitbucket-server/index.spec.ts

lib/config/presets/bitbucket/index.spec.ts

lib/config/presets/gitea/index.spec.ts

lib/config/presets/github/index.spec.ts

lib/config/presets/gitlab/index.spec.ts

lib/config/presets/index.spec.ts

lib/config/presets/internal/index.spec.ts

lib/config/presets/local/index.spec.ts

lib/config/presets/npm/index.spec.ts

lib/config/presets/util.spec.ts

lib/config/secrets.spec.ts

lib/config/validation-helpers/managers.spec.ts