Merge bitcoin/bitcoin#33102: fuzz: cover BanMan::IsDiscouraged

c2ed576d2c fuzz: cover BanMan::IsDiscouraged (brunoerg)

Pull request description:

  This PR adds fuzz coverage for the `IsDiscouraged` function in the banman target. This is the only function missing from `BanMan`.

ACKs for top commit:
  maflcko:
    lgtm ACK c2ed576d2c
  marcofleon:
    ACK c2ed576d2c

Tree-SHA512: 1dc5fc138f89413c46ed41195940f4c578ef996ce84595271b7433cae8a8f576205b649b493a7ec4804c712327d6c77b1004ba116b0144916377042adaaf6c5f

src/test/fuzz/banman.cpp

@@ -117,6 +117,9 @@ FUZZ_TARGET(banman, .init = initialize_banman)
                 },
                 [&] {
                     ban_man.Discourage(ConsumeNetAddr(fuzzed_data_provider));
+                },
+                [&] {
+                    ban_man.IsDiscouraged(ConsumeNetAddr(fuzzed_data_provider));
                 });
         }
         if (!force_read_and_write_to_err) {