Stale native Iceberg write wording in iceberg-writes.md #5641

Describe the bug

The accepted-divergences section of docs/source/user-guide/latest/iceberg-writes.md carries an "Operational caveat" saying native Iceberg writes leave partition paths unescaped (region=a/b where iceberg-java writes region=a%2Fb), and the eligibility table's "partition spec" row points at it.

That divergence disappears once #5636 bumps the iceberg-rust pin past apache/iceberg-rust#2875, which makes partition_to_path use the same form-urlencoding table as iceberg-java's PartitionSpec.partitionToPath. The caveat and the table cross-reference should go with it.

(Earlier drafts of this issue also listed a stale "the native writer is not yet wired in" paragraph and a stale note about the metrics-mode restriction; both were already corrected on main by #5361, so only the escaping entry remains.)

Steps to reproduce

Read the "Accepted divergences" section of iceberg-writes.md on main.

Expected behavior

No divergence is listed for partition paths, and the "partition spec" eligibility row reads "any".

Additional context

Part of the native Iceberg writes epic, #5649. Fixed together with #5636.