tests(iroh-net): Remove a flaky test (n0-computer#2379)

## Description

This flakyness seems to have been successfully addressed by the
staggered DNS lookup.  Converting this test to that basically results
in the same code as the next test: test_dns_lookup_ipv4_ipv6.  So just
remove this test as it no longer provides value.

## Breaking Changes

<!-- Optional, if there are any breaking changes document them,
including how to migrate older code. -->

## Notes & open questions

See n0-computer#2380 for the flaky test.

## Change checklist

- [x] Self-review.
- ~~[ ] Documentation updates if relevant.~~
- [x] Tests if relevant.
- ~~[ ] All breaking changes documented.~~

iroh-net/src/dns.rs

@@ -387,17 +387,6 @@ pub(crate) mod tests {
     const TIMEOUT: Duration = Duration::from_secs(5);
     const STAGGERING_DELAYS: &[u64] = &[200, 300];
 
-    #[tokio::test]
-    #[cfg_attr(target_os = "windows", ignore = "flaky")]
-    async fn test_dns_lookup_basic() {
-        let _logging = iroh_test::logging::setup();
-        let resolver = default_resolver();
-        let res = resolver.lookup_ip(NA_RELAY_HOSTNAME).await.unwrap();
-        let res: Vec<_> = res.iter().collect();
-        assert!(!res.is_empty());
-        dbg!(res);
-    }
-
     #[tokio::test]
     async fn test_dns_lookup_ipv4_ipv6() {
         let _logging = iroh_test::logging::setup();

iroh/src/node.rs

@@ -426,6 +426,7 @@ mod tests {
     }
 
     #[cfg(feature = "fs-store")]
+    #[ignore = "flaky"]
     #[tokio::test]
     async fn test_default_author_persist() -> Result<()> {
         use crate::util::path::IrohPaths;