feat: allowing post method into auth refresh api

Signed-off-by: Antonio Musolino <antoniomusolino007@gmail.com>

.changeset/ten-cobras-wash.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-auth-backend': minor
+---
+
+Allowed post method on /refresh path

docs/auth/add-auth-provider.md

@@ -350,6 +350,7 @@ router.get('/auth/providerA/handler/frame');
 router.post('/auth/providerA/handler/frame');
 router.post('/auth/providerA/logout');
 router.get('/auth/providerA/refresh'); // if supported
+router.post('/auth/providerA/refresh'); // if supported
 ```
 
 As you can see each endpoint is prefixed with both `/auth` and its provider

plugins/auth-backend/src/service/router.ts

@@ -140,6 +140,7 @@ export async function createRouter(
         }
         if (provider.refresh) {
           r.get('/refresh', provider.refresh.bind(provider));
+          r.post('/refresh', provider.refresh.bind(provider));
         }
 
         router.use(`/${providerId}`, r);