Merge #19464: net: remove -banscore configuration option

06059b0c2a net: rename DEFAULT_BANSCORE_THRESHOLD to DISCOURAGEMENT_THRESHOLD (Jon Atack)
1d4024bca8 net: remove -banscore configuration option (Jon Atack)

Pull request description:

  per https://github.com/bitcoin/bitcoin/pull/19219#issuecomment-652684340, https://github.com/bitcoin/bitcoin/pull/19219#discussion_r443074487 and https://github.com/bitcoin/bitcoin/pull/19219#issuecomment-652699592. Edit: now split into 3 straightforward PRs:
  - net: remove -banscore configuration option (this PR)
  - rpc: deprecate banscore field in getpeerinfo (#19469, *merged*)
  - gui: no longer display banscores (TBA in the gui repo)

ACKs for top commit:
  MarcoFalke:
    review ACK 06059b0c2a 📙
  vasild:
    ACK 06059b0c

Tree-SHA512: 03fad249986e0896697033fbb8ba2cbfaae7d7603b1fb2a38b3d41db697630d238623f4d732b9098c82af249ce5a1767dd432b7ca0fec10544e23d24fbd57c50

test/functional/p2p_leak.py

@@ -26,7 +26,7 @@ from test_framework.util import (
     wait_until,
 )
 
-banscore = 10
+DISCOURAGEMENT_THRESHOLD = 100
 
 
 class CLazyNode(P2PInterface):
@@ -70,7 +70,7 @@ class CNodeNoVersionBan(CLazyNode):
     # NOTE: implementation-specific check here. Remove if bitcoind ban behavior changes
     def on_open(self):
         super().on_open()
-        for i in range(banscore):
+        for _ in range(DISCOURAGEMENT_THRESHOLD):
             self.send_message(msg_verack())
 
 # Node that never sends a version. This one just sits idle and hopes to receive
@@ -106,7 +106,6 @@ class P2PVersionStore(P2PInterface):
 class P2PLeakTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
-        self.extra_args = [['-banscore=' + str(banscore)]]
 
     def run_test(self):
         no_version_bannode = self.nodes[0].add_p2p_connection(CNodeNoVersionBan(), send_version=False, wait_for_verack=False)