Disable fsync for postgres too

Summary [ 166.110s] 1453 tests run: 1453 passed (1 slow), 15 skipped

Above is before this commit, below is after.

     Summary [ 140.410s] 1453 tests run: 1453 passed, 15 skipped

The mechanism here is the same as for the metastore tests. By skipping fsync we can run the tests much faster, and fsync doesn't matter in tests. Unless you're testing postgres itself I guess

scripts/test-infra.sh

@@ -42,7 +42,10 @@ start_infra() {
         -P \
         --label tranquil_pds_test=true \
         postgres:18-alpine \
-        -c max_connections=500 >/dev/null
+        -c max_connections=500 \
+        -c fsync=off \
+        -c synchronous_commit=off \
+        -c full_page_writes=off >/dev/null
     echo "Waiting for services to be ready..."
     for i in {1..30}; do
         if $CONTAINER_CMD exec "${CONTAINER_PREFIX}-postgres" pg_isready -U postgres >/dev/null 2>&1; then