fix(azuresink): track recreated blobs for cleanup on write failure

handleExistingBlob deletes and recreates the blob when overwrite is
needed, but freshlyCreated was only set on the initial Create success
path. Set freshlyCreated = needsWrite after handleExistingBlob so
recreated blobs are also cleaned up on content write failure.

weed/replication/sink/azuresink/azure_sink.go

@@ -147,6 +147,8 @@ func (g *AzureSink) CreateEntry(key string, entry *filer_pb.Entry, signatures []
 			if handleErr != nil {
 				return handleErr
 			}
+			// handleExistingBlob recreates the blob when needsWrite is true
+			freshlyCreated = needsWrite
 		} else {
 			return fmt.Errorf("azure create append blob %s/%s: %w", g.container, key, err)
 		}