As a follow-up to #13550 and #22060, replace the mostly unreachable testnet torv3 hardcoded seeds from v0.22 with new ones that are consistently reachable recently and that have service bit 1 set.
This needs to be done before v24.0 to make sure onion-only testnet nodes can still connect to the network.
Ways to test:
- 
Re-generate src/chainparamsseeds.hwithcd contrib/seeds && python3 generate-seeds.py . > ../../src/chainparamsseeds.h, check if git tree stays the same
- 
Re-compile and create a new testnet node with bitcoind -testnet -dnsseed=0 -onlynet=onion -proxy=127.0.0.1:9050(or delete~/.bitcoin/testnet3/peers.datand launch bitcoind with-testnet -dnsseed=0). Make sure there are noaddnode=in yourbitcoin.conf. The debug log should print “Adding fixed seeds”. Check if the node is able to connect to the network and get blocks with for ex.watch -t ./src/bitcoin-cli -testnet -rpcwait -netinfo 4
- 
Check the addrman contains the seeds by running for ex. bitcoin-cli -rpcwait -testnet getnodeaddresses 0 onion | jq -r '.[] | (.address + ":" + (.port|tostring) + " " + (.services|tostring))' | sort
- 
Check if the addresses are connectable, for ex. with this python script by laanwj: 
0#!/usr/bin/env python3
1import pprint
2import subprocess
3with open('contrib/seeds/nodes_test.txt') as f:
4    for line in (line for line in (line.rstrip().split('#', 1)[0] for line in f) if line):
5        pprint.pprint(line)
6        subprocess.call(["nc", "-v", "-x", "127.0.0.1:9050", "-z"] + line.split(':'))
Thanks to satsie (Stacie Waleyko) for help with the list.