Merge bitcoin/bitcoin#26054: test: verify best blockhash after invalidating an unknown block

4f67336 test: verify best blockhash after invalidating an unknown block (brunoerg)

Pull request description:

  Fixes #26051

  Verify the best blockhash is the same after invalidating an unknown block, not the whole `getchaintip` response.

ACKs for top commit:
  instagibbs:
    ACK 4f67336

Tree-SHA512: 2d71743c1d3a317ef7b750f88437df71d1aed2728d9edac8b763a343406e168b97865ab25ec4c89caf09d002e076458376618cbd0845496375f7179633c88af9

Author: MacroFake

test/functional/rpc_invalidateblock.py

@@ -85,9 +85,8 @@ def run_test(self):
         assert_equal(self.nodes[1].getbestblockhash(), blocks[-1])
 
         self.log.info("Verify that invalidating an unknown block throws an error")
-        chain_tips = self.nodes[1].getchaintips()
         assert_raises_rpc_error(-5, "Block not found", self.nodes[1].invalidateblock, "00" * 32)
-        assert_equal(chain_tips, self.nodes[1].getchaintips())
+        assert_equal(self.nodes[1].getbestblockhash(), blocks[-1])
 
 
 if __name__ == '__main__':