Warn on full disk

[eivindjahren]

Issue
Resolves #8921

The following is presented if disk is "close" to full:

• 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 'pytest tests/ert/unit_tests -n logical -m "not integration_test"')

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

[eivindjahren]

Supersedes #9193

[larsevj]

🚀

[codspeed-hq]

CodSpeed Performance Report

Merging #9745 will improve performances by 10.96%

_{Comparing eivindjahren:warn_on_full_disk (6004ec7) with main (56b3381)}

Summary

⚡ 1 improvements
✅ 23 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	eivindjahren:warn_on_full_disk	Change
⚡	test_load_from_context[gen_x: 20, sum_x: 20 reals: 10]	7.1 ms	6.4 ms	+10.96%