test(config): skip the rate-limit parse-error tests under miri

serde_json finds a parse error's line and column with memrchr, which
rounds down to a word boundary and reads aligned usizes. The input is a
String, so miri's -Zmiri-symbolic-alignment-check only knows alignment 1
and reports those reads as undefined behavior, failing
check/miri/powerpc64 in the merge queue for the three tests that feed
the parser invalid policies.

Real reads are aligned. Ignore the three tests under miri, as the repo
does for other tests miri cannot run, rather than relax the alignment
check for every crate.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Daniel Noland <daniel@githedgehog.com>

Author: daniel-noland

config/src/converters/k8s/config/ratelimit/tests.rs

@@ -234,6 +234,10 @@ fn acl_match_supports_protocol_ports_and_subnet_references() {
 }
 
 #[test]
+#[cfg_attr(
+    miri,
+    ignore = "serde_json locates parse errors with memchr, whose aligned word reads miri's symbolic alignment check refuses"
+)]
 fn acl_match_supports_tcp_filters() {
     use crate::external::overlay::acl::{AclProtoMatch, AclTcpFlagsMatch};
     use net::tcp::TcpFlags;
@@ -269,6 +273,10 @@ fn acl_match_supports_tcp_filters() {
 }
 
 #[test]
+#[cfg_attr(
+    miri,
+    ignore = "serde_json locates parse errors with memchr, whose aligned word reads miri's symbolic alignment check refuses"
+)]
 fn invalid_meter_settings_are_refused() {
     for (meter, expected) in [
         (json!({}), "needs bits or pkts"),
@@ -321,6 +329,10 @@ fn invalid_meter_settings_are_refused() {
 }
 
 #[test]
+#[cfg_attr(
+    miri,
+    ignore = "serde_json locates parse errors with memchr, whose aligned word reads miri's symbolic alignment check refuses"
+)]
 fn unknown_versions_rules_and_fields_are_refused() {
     let base = policy(json!({"pkts": {"rate": "1k"}}));
     for (pointer, value) in [