Re-added missing astrid flags to UnwindHeimdall (#12582)

This fixes this issue when running main with bor_heimdall stage:

```
[EROR] [10-31|09:13:03.527] Staged Sync                              err="[3/9 BorHeimdall] unexpected missing first processed block info entry when unwinding"
```

It was caused by a miss-merge after this PR:
#12148

---------

Co-authored-by: taratorio <94537774+taratorio@users.noreply.github.com>

polygon/bor/bordb/prune.go

@@ -103,7 +103,7 @@ func UnwindHeimdall(ctx context.Context, heimdallStore heimdall.Store, bridgeSto
 		}
 	}
 
-	if !unwindCfg.KeepEventProcessedBlocks {
+	if !unwindCfg.KeepEventProcessedBlocks && unwindCfg.Astrid {
 		if err := bridge.UnwindEventProcessedBlocks(tx, unwindPoint); err != nil {
 			return err
 		}