fix(typescript-axios): add explicit return type to avoid TS2527 error

axios 1.7.5+ exports a unique symbol that TypeScript cannot infer
through the generated createRequestFunction. Adding an explicit
': Promise<R>' return type on the inner arrow function and casting the
result prevents TS from exposing the inaccessible symbol.

Upstream fix: OpenAPITools/openapi-generator#24526 (not yet in v7.16.0).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: dvacca-onfido

generators/typescript-axios/templates/common.mustache

@@ -98,9 +98,10 @@ export const toPathString = function (url: URL) {
     return url.pathname + url.search + url.hash
 }
 
+{{! Explicit return type annotation to avoid TS2527 with axios 1.7.5+ unique symbol}}
 export const createRequestFunction = function (axiosArgs: RequestArgs, globalAxios: AxiosInstance, BASE_PATH: string, configuration?: Configuration) {
-    return <T = unknown, R = AxiosResponse<T>>(axios: AxiosInstance = globalAxios, basePath: string = BASE_PATH) => {
+    return <T = unknown, R = AxiosResponse<T>>(axios: AxiosInstance = globalAxios, basePath: string = BASE_PATH): Promise<R> => {
         const axiosRequestArgs = {...axiosArgs.options, url: (axios.defaults.baseURL ? '' : configuration?.basePath ?? basePath) + axiosArgs.url};
-        return axios.request<T, R>(axiosRequestArgs);
+        return axios.request<T, R>(axiosRequestArgs) as Promise<R>;
     };
 }