Use COINBASE_MATURITY constant in functional tests.

test/functional/p2p_eviction.py

@@ -15,7 +15,11 @@ Therefore, this test is limited to the remaining protection criteria.
 
 import time
 
-from test_framework.blocktools import create_block, create_coinbase
+from test_framework.blocktools import (
+    COINBASE_MATURITY,
+    create_block,
+    create_coinbase,
+)
 from test_framework.messages import CTransaction, FromHex, msg_pong, msg_tx
 from test_framework.p2p import P2PDataStore, P2PInterface
 from test_framework.test_framework import BitcoinTestFramework
@@ -45,7 +49,7 @@ class P2PEvict(BitcoinTestFramework):
         protected_peers = set()  # peers that we expect to be protected from eviction
         current_peer = -1
         node = self.nodes[0]
-        node.generatetoaddress(101, node.get_deterministic_priv_key().address)
+        node.generatetoaddress(COINBASE_MATURITY + 1, node.get_deterministic_priv_key().address)
 
         self.log.info("Create 4 peers and protect them from eviction by sending us a block")
         for _ in range(4):