Resolve polars asof warning

[larsevj]

Get the following warning now:

/data/komodo_dev/ert/src/ert/storage/local_ensemble.py:986: UserWarning: left key of asof join is not sorted.

This can lead to invalid results. Ensure the asof key is sorted
  ).join_asof(
/data/komodo_dev/ert/src/ert/storage/local_ensemble.py:986: UserWarning: right key of asof join is not sorted.

This can lead to invalid results. Ensure the asof key is sorted
  ).join_asof(

• PR title captures the intent of the changes, and is fitting for release notes.
• Added appropriate release note label
• Commit history is consistent and clean, in line with the contribution guidelines.
• Make sure unit tests pass locally after every commit (git rebase -i main --exec 'just rapid-tests')

When applicable

• When there are user facing changes: Updated documentation
• New behavior or changes to existing untested code: Ensured that unit tests are added (See Ground Rules).
• Large PR: Prepare changes in small commits for more convenient review
• Bug fix: Add regression test for the bug
• Bug fix: Create Backport PR to latest release

[codspeed-hq]

CodSpeed Performance Report

Merging #9912 will improve performances by 10.32%

_{Comparing larsevj:resolve_polars_asof_warning (6cf6192) with main (5dfbbd8)}

Summary

⚡ 1 improvements
✅ 24 untouched benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	test_load_from_context[gen_x: 20, sum_x: 20 reals: 10]	7 ms	6.4 ms	+10.32%