flaky test in `influxdb3_write` crate - write_buffer::tests::returns_chunks_across_parquet_and_buffered_data

To reproduce this, run the following command from the root of the repo:

```
while cargo nextest run --workspace write_buffer::tests::returns_chunks_across_parquet_and_buffered_data ;do echo "trying again" ;done
```

The failure output looks like the following:

```
failures:
write_buffer::tests::returns_chunks_across_parquet_and_buffered_data

test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 53 filtered out; finished in 0.10s

--- STDERR: influxdb3_write write_buffer::tests::returns_chunks_across_parquet_and_buffered_data ---

thread 'write_buffer::tests::returns_chunks_across_parquet_and_buffered_data' panicked at influxdb3_write/src/write_buffer/mod.rs:1515:9:
assertion failed: `(left == right)`:

expected:

[
"+-----+----------------------+",
"| bar | time |",
"+-----+----------------------+",
"| 1.0 | 1970-01-01T00:00:10Z |",
"| 2.0 | 1970-01-01T00:01:05Z |",
"| 3.0 | 1970-01-01T00:02:27Z |",
"| 4.0 | 1970-01-01T00:04:10Z |",
"| 5.0 | 1970-01-01T00:05:00Z |",
"| 6.0 | 1970-01-01T00:05:30Z |",
"+-----+----------------------+",
]
actual:

[
"+-----+----------------------+",
"| bar | time |",
"+-----+----------------------+",
"| 1.0 | 1970-01-01T00:00:10Z |",
"| 2.0 | 1970-01-01T00:01:05Z |",
"| 4.0 | 1970-01-01T00:04:10Z |",
"| 5.0 | 1970-01-01T00:05:00Z |",
"| 6.0 | 1970-01-01T00:05:30Z |",
"+-----+----------------------+",
]

Diff < left / right > :
[
"+-----+----------------------+",
"| bar | time |",
"+-----+----------------------+",
"| 1.0 | 1970-01-01T00:00:10Z |",
"| 2.0 | 1970-01-01T00:01:05Z |",
< "| 3.0 | 1970-01-01T00:02:27Z |",
"| 4.0 | 1970-01-01T00:04:10Z |",
"| 5.0 | 1970-01-01T00:05:00Z |",
"| 6.0 | 1970-01-01T00:05:30Z |",
"+-----+----------------------+",
]
```

Start by running the provided cargo nextest command from the repository root and inspect influxdb3_write/src/write_buffer/mod.rs around line 1515, including write_buffer::tests::returns_chunks_across_parquet_and_buffered_data. Reproduce the missing row and trace why the test sometimes omits it; done means the test passes consistently with all six expected rows.

Written by the indexing model from the issue text.