fix(tracing): Don't set method multiple times

Author: AbhiPrasad

packages/nextjs/test/integration/test/client/tracingFetch.test.ts

@@ -31,7 +31,7 @@ test('should correctly instrument `fetch` for performance tracing', async ({ pag
   expect(transaction[0].spans).toEqual(
     expect.arrayContaining([
       expect.objectContaining({
-        data: { method: 'GET', url: 'http://example.com', type: 'fetch' },
+        data: { 'http.method': 'GET', url: 'http://example.com', type: 'fetch' },
         description: 'GET http://example.com',
         op: 'http.client',
         parent_span_id: expect.any(String),

packages/tracing-internal/src/browser/request.ts

@@ -191,13 +191,14 @@ export function fetchCallback(
   const activeTransaction = currentSpan && currentSpan.transaction;
 
   if (currentSpan && activeTransaction) {
+    const { method, url } = handlerData.fetchData;
     const span = currentSpan.startChild({
       data: {
-        ...handlerData.fetchData,
+        url,
         type: 'fetch',
-        'http.method': handlerData.fetchData.method,
+        'http.method': method,
       },
-      description: `${handlerData.fetchData.method} ${handlerData.fetchData.url}`,
+      description: `${method} ${url}`,
       op: 'http.client',
     });