[bug](iceberg) fix iceberg sink writer with spill report error

[zhangstar333]

What problem does this PR solve?

Problem Summary:

spill thread with write thread is different, so add mutex in the write function.

mysql> create table web_sales
    -> order by (ws_sold_date_sk, ws_item_sk, ws_order_number)
    -> PROPERTIES (
    ->   'write-format'='parquet'
    -> )
    -> as select * from tpcds_sf1000_parquet.web_sales;
ERROR 1105 (HY000): errCode = 2, detailMessage = (172.20.49.239)[INTERNAL_ERROR][E6] Size of permutation (40800) is less than required (48960)        0#  doris::Exception::Exception(int, std::basic_string_view<char, std::char_traits<char> > const&, bool) at /home/zcp/repo_center/doris_branch-4.1/doris/be/src/common/exception.cpp:0
        1#  doris::Exception::Exception(int, std::basic_string_view<char, std::char_traits<char> > const&) at /usr/local/ldb-toolchain-v0.26/bin/../lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/basic_stri
mysql>

Release note

None

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
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