Only mark servers as offline if they fail pings 3+ times (#5664)

* wip: online status fix

* use INCR

* properly clear cache

apps/labrinth/src/env.rs

@@ -293,4 +293,5 @@ vars! {
     SERVER_PING_RETRIES: usize = 3usize;
     SERVER_PING_MIN_INTERVAL_SEC: u64 = 30u64 * 60;
     SERVER_PING_TIMEOUT_MS: u64 = 3u64 * 1000;
+    SERVER_PING_MAX_FAIL_COUNT: u64 = 3u64;
 }