AFAICT, as of commit a0a422c,  we have 2 different logics to evict outbound peers : lagging-chain (`ConsiderEviction`) and (`CheckForStaleTipAndEvictPeers`). The former to sanitize out lazy/buggy peers who have never sent us a valid header and are always staying behind our tip, the latter triggered in case of stale tip due to block variance to seek a better chain by rotating our outbound peers if we already reach an outbound limit (`EvictExtraOutboundPeers`).

Block-relay-only peers were introduced by #15719. Contrary to outbound full-relay peers who provided us at least a useful header, they're not protected by lagging-chain eviction.

We actually have a comment inside `ProcessHeadersMessage` indicating the contrary behavior. We should either document cleanly that block-relay-only aren't protected or effectively extend the scope of protection to them.

Hinted during #19724 review, see https://github.com/bitcoin/bitcoin/pull/19724#discussion_r475144532
{
    auto it = g_already_asked_for.find(gtxid.GetHash());
    if (it == g_already_asked_for.end()) {
        g_already_asked_for.insert(std::make_pair(gtxid.GetHash(), request_time));
    } else {
        g_already_asked_for.update(it, request_time);
    }
}
std::chrono::microseconds CalculateTxGetDataTime(const GenTxid& gtxid, std::chrono::microseconds current_time, bool use_inbound_delay, bool use_txid_delay) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
    std::chrono::microseconds process_time;
    const auto last_request_time = GetTxRequestTime(gtxid);
    
    if (last_request_time.count() == 0) {
        process_time = current_time;
    } else {
        
        
        process_time = last_request_time + GETDATA_TX_INTERVAL + GetRandMicros(MAX_GETDATA_RANDOM_DELAY);
    }
    
    if (use_inbound_delay) process_time += INBOUND_PEER_TX_DELAY;
    
    if (use_txid_delay) process_time += TXID_RELAY_DELAY;
    return process_time;
}
void RequestTx(CNodeState* state, const GenTxid& gtxid, std::chrono::microseconds current_time) EXCLUSIVE_LOCKS_REQUIRED(cs_main)