Orval: RCE via servers[].url -> unescaped request-URL template literal (with getBaseUrlFromSpecification)

Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, an unescaped backtick in servers[0].url is emitted into request URL template literals generated when output.baseUrl.getBaseUrlFromSpecification is enabled without safe encoding. This permits attacker-controlled JavaScript to be evaluated when a generated request or URL-builder function is called, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/core/src/getters/route.ts function getFullRoute. This issue is fixed in version 8.21.0.