Merge pull request #4762 from crobibero/api-file-return

Fix openapi file schema

(cherry picked from commit b56feac841)
Signed-off-by: Joshua M. Boniface <joshua@boniface.me>

Jellyfin.Server/Filters/FileResponseFilter.cs

@@ -14,7 +14,8 @@ namespace Jellyfin.Server.Filters
         {
             Schema = new OpenApiSchema
             {
-                Type = "file"
+                Type = "string",
+                Format = "binary"
             }
         };