repository: make N=1 chunk size assumption explicit in list(), refs #8572

info.size is the on-disk pack file size, which equals the chunk size only
when N=1 (one chunk per pack).  Extract it into a named variable with a
comment so the assumption is visible and easy to fix when N>1 is introduced.

Author: mr-raj12

src/borg/repository.py

@@ -467,7 +467,8 @@ def list(self, limit=None, marker=None):
                 pack_id = hex_to_bin(info.name)
                 chunk_id = pack_id  # N=1: chunk_id == pack_id
                 if collect:
-                    result.append((chunk_id, info.size))
+                    chunk_size = info.size  # only correct for N=1
+                    result.append((chunk_id, chunk_size))
                     if len(result) == limit:
                         break
                 elif chunk_id == marker: