Run test_packet_buffer_writer through miri

ci/test-miri.sh

@@ -6,8 +6,8 @@ source ci/_
 source ci/rust-version.sh nightly
 
 # miri is very slow; so only run very few of selective tests!
+_ cargo "+${rust_nightly}" miri test -p solana-packet -- test_packet_buffer_writer
 _ cargo "+${rust_nightly}" miri test -p solana-program -- hash:: account_info::
-
 _ cargo "+${rust_nightly}" miri test -p solana-unified-scheduler-logic
 
 # run intentionally-#[ignored] ub triggering tests for each to make sure they fail