Do not set `Accept` header twice (#28598)

Revert #28550

Don't add the `Accept` header twice.

modules/lfs/http_client.go

@@ -79,10 +79,7 @@ func (c *HTTPClient) batch(ctx context.Context, operation string, objects []Poin
 		return nil, err
 	}
 
-	req, err := createRequest(ctx, http.MethodPost, url, map[string]string{
-		"Content-Type": MediaType,
-		"Accept":       MediaType,
-	}, payload)
+	req, err := createRequest(ctx, http.MethodPost, url, map[string]string{"Content-Type": MediaType}, payload)
 	if err != nil {
 		return nil, err
 	}