Merge #16538: test: Add missing sync_blocks to feature_pruning

fa566b2 test: Add missing sync_blocks to feature_pruning (MarcoFalke)

Pull request description:

  Fixes #16537
  Fixes #16520

ACKs for top commit:
  promag:
    ACK fa566b2.
  jonatack:
    ACK fa566b2. These past few months I have been seeing intermittent failures with this test on master. Ran `(for i in {1..40}; do test/functional/feature_pruning.py -l=debug; done)` overnight with this change; no failures.

Tree-SHA512: 5181d5ea525f43ad09e1c8b9ae72e32219f483948854c6dc07dda24b790cbdf4012e586253a0e158a71a980d1ca9f5fdf06aafbe95b8ea3d9154ef2c8687395b

Author: MarcoFalke

test/functional/feature_pruning.py

@@ -204,6 +204,7 @@ def reorg_test(self):
         self.log.info("Mine 220 more large blocks so we have requisite history")
 
         mine_large_blocks(self.nodes[0], 220)
+        self.sync_blocks(self.nodes[0:3], timeout=120)
 
         usage = calc_usage(self.prunedir)
         self.log.info("Usage should be below target: %d" % usage)