fuzzing: fix oss-fuzz fuzzer (#30845)

The fuzzer added recenly to fuzz the eth handler doesn't
build on oss-fuzz, because it also has dependencies in the peer_test.go.

This change fixes it, I hope, by adding that file also for preprocessing.

oss-fuzz.sh

@@ -234,10 +234,6 @@ compile_fuzzer github.com/ethereum/go-ethereum/tests/fuzzers/secp256k1 \
 
 compile_fuzzer github.com/ethereum/go-ethereum/eth/protocols/eth \
   FuzzEthProtocolHandlers fuzz_eth_protocol_handlers \
-  $repo/eth/protocols/eth/handler_test.go
+  $repo/eth/protocols/eth/handler_test.go,$repo/eth/protocols/eth/peer_test.go
 
 
-#compile_fuzzer tests/fuzzers/vflux      FuzzClientPool fuzzClientPool
-#compile_fuzzer tests/fuzzers/difficulty Fuzz fuzzDifficulty
-#compile_fuzzer tests/fuzzers/les        Fuzz fuzzLes
-