make EDF writer handle anonymized meas_date

[drammock]

PR Description

EDF/BDF formats restrict the startdate (equivalent of meas_date) to be 1985-01-01 or later, which conflicts with the BIDS standard for anonymization (which requires anonymized dates to be before 1920-01-01). In #669 a decision was made to write EDF(+) files that violate the BIDS standard but honor the EDF standard (making them viewable in EDFBrowser), while writing the BIDS-compliant anonymized date in scans.tsv. However, it was only implemented in cases where the anonymized data started out in EDF format (i.e., only mne_bids/copyfiles.py was changed). In cases where the data start in another format, are anonymized, and then written to EDF(+), the result will be an invalid EDF file. This PR fixes that. As with #669, the BIDS-compliant anonymized date will still be written to scans.tsv; only the EDF file itself will be modified.

The PR also does a small internal refactor to allow both EDF and BDF writing; this is needed for #1129, because EMG modality will have BDF(+) as a RECOMMENDED format.

Merge checklist

Maintainer, please confirm the following before merging.
If applicable:

• All comments are resolved
• This is not your own PR
• All CIs are happy
• PR title starts with [MRG]
• whats_new.rst is updated
• New contributors have been added to CITATION.cff
• PR description includes phrase "closes <#issue-number>"

[codecov]

Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.96%. Comparing base (dd3c984) to head (d9018a2).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
mne_bids/tests/test_write.py	90.90%	2 Missing ⚠️
mne_bids/write.py	83.33%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1479   +/-   ##
=======================================
  Coverage   96.96%   96.96%           
=======================================
  Files          43       43           
  Lines       10100    10119   +19     
=======================================
+ Hits         9793     9812   +19     
  Misses        307      307           

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[drammock]

arg, still getting mne_bids/tests/test_fileio.py::test_lock_refcount_multiprocess - AssertionError

https://github.com/mne-tools/mne-bids/actions/runs/19348373149/job/55354332061?pr=1479#step:18:541

@bruAristimunha

[drammock]

@sappelhoff there's a stdlib feature of datetime module only available on python 3.11+, making the 3.10 CIs fail

https://github.com/mne-tools/mne-bids/actions/runs/19348373149/job/55354332026?pr=1479#step:22:376

The string is valid ISO format, this was a bug-ish in python prior to 3.11. Is this justification enough to:

1. bump the min CIs to use 3.11
2. bump the package min python version to 3.11
3. neither (1) or (2), just put a guard on that particular test

?

[sappelhoff]

I would be happy to have the min python pushed to 3.11.

It's still 11 months to go until 3.10's EOL, but we can also make our lives a tiny bit easier.

[drammock]

I would be happy to have the min python pushed to 3.11.

will do

It's still 11 months to go until 3.10's EOL [...]

FWIW SPEC-0 would recommend already setting 3.12 as the minimum. So switching from 3.10 to 3.11 is already a bit conservative from the perspective of our ecosystem peers.

[drammock]

OK CIs are happy except for one more case of
mne_bids/tests/test_fileio.py:545: in test_lock_refcount_multiprocess (which we're handling separately in #1480). The 6 "pending" checks are cruft due to the CI job names changing when I changed the Python version, and the codecov/patch result is spurious (no new missed lines).

Ready for review/merge

[sappelhoff]

Thanks a lot @drammock

[sappelhoff]

Ah

this actually needs some changes to our required checks: https://github.com/mne-tools/mne-bids/settings/branch_protection_rules/2696889

I can have a look at this soon

[drammock]

@sappelhoff I updated the branch protection rules to replace the 3.10 jobs with the corresponding 3.11 jobs.

[sappelhoff]

Thank you, Dan.