Fix: derive supported formats dynamically in ImageWriter error message

Author: Talhax55z

monai/data/image_writer.py

@@ -116,7 +116,12 @@ def resolve_writer(ext_name, error_if_not_found=True) -> Sequence:
         except Exception:  # other writer init errors indicating it exists
             avail_writers.append(_writer)
     if not avail_writers and error_if_not_found:
-        raise OptionalImportError(f"No ImageWriter backend found for {fmt}. Please install a suitable package: 'nibabel' (for .nii/.nii.gz), 'itk' (for .nrrd/.mha), or 'Pillow' (for .png/.jpg).")
+        _supported = ", ".join(sorted(SUPPORTED_WRITERS.keys()))
+        raise OptionalImportError(
+            f"No ImageWriter backend found for {fmt}. "
+            f"Supported formats: {_supported}. "
+            f"Please install a suitable package such as 'nibabel', 'itk', or 'Pillow'."
+        )
     writer_tuple = ensure_tuple(avail_writers)
     SUPPORTED_WRITERS[fmt] = writer_tuple
     return writer_tuple