Skip L2 processing if no good times are found

[vmartinez-cu]

This PR updates L2 processing to exit processing early and return an empty list if no good times are found in the l1b input dataset.

File changes

• glows_l2_data.py - added a factory class method that checks if good times exist before proceeding with creating the l2 histogram data class. If no good times are found, it returns None

• glows_l2.py - updated call to the histogram data class to use new class method to create the instance

Testing

• test_glows_l2.py - updated existing unit tests to include coverage for when there are no good times in the data

Closes #2372

[Copilot]

Pull request overview

This PR implements early exit from L2 processing when no good times are found in the L1B input dataset, addressing issue #2372. The solution uses a factory method pattern to validate data before processing and returns an empty list instead of creating invalid output files.

Changes:

• Added a factory class method HistogramL2.create() that checks for good times before instantiation
• Refactored HistogramL2.__init__() to accept pre-filtered data, removing validation logic from the constructor
• Updated glows_l2() to handle None return from factory method and log warnings appropriately

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
imap_processing/glows/l2/glows_l2_data.py	Added factory method create() for validation and filtering; refactored constructor to accept only good data; fixed spelling in error message
imap_processing/glows/l2/glows_l2.py	Updated to use factory method; added logging for no-good-times case; returns empty list when appropriate
imap_processing/tests/glows/test_glows_l2.py	Added test case for HistogramL2.create() returning None when no good times exist

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.