Consolidate CI case configuration to single source of truth

[Copilot]

Description

CI test case configurations were maintained in two locations: individual case YAMLs with skip_ci_on_hosts tags and hardcoded matrices in gitlab-ci-hosts.yml. This created maintenance burden when adding test cases or modifying host support.

Changes

Automation Script (dev/ci/scripts/utils/generate_host_case_matrix.py)

• Parses skip_ci_on_hosts from case YAMLs in dev/ci/cases/pr/
• Generates host-specific case matrices for GitLab CI
• Supports in-place update (--update), dry-run (--dry-run), and specific host selection (--hosts)

Configuration (dev/ci/gitlab-ci-hosts.yml)

• Added auto-generated header warning against manual edits
• Regenerated matrices from case YAMLs (content unchanged, now automated)

Documentation

• dev/ci/README-case-configuration.md: Comprehensive guide for managing test cases
• Updated dev/ci/README-CI-Pipeline.md with cross-references

Usage

Adding a new test case:

# 1. Create case YAML with skip_ci_on_hosts section
# 2. Regenerate matrices
python dev/ci/scripts/utils/generate_host_case_matrix.py --update
# 3. Commit both files

Existing test_ci_matrix_validation.py validates synchronization between case YAMLs and generated matrices.

Resolves #<issue_number>

Type of change

• Maintenance (code refactor, clean-up, new CI test, etc.)

Change characteristics

• Is this a breaking change (a change in existing functionality)? NO
• Does this change require a documentation update? YES (included)
• Does this change require an update to any of the following submodules? NO

How has this been tested?

• All validation tests pass (7/7 in test_ci_matrix_validation.py)
• YAML syntax validated
• New case addition workflow verified locally
• CodeQL security scan: 0 alerts
• Code style: pycodestyle compliant

Checklist

• Any dependent changes have been merged and published
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have documented my code, including function, input, and output descriptions
• My changes generate no new warnings
• New and existing tests pass with my changes
• This change is covered by an existing CI test or a new one has been added
• Any new scripts have been added to the .github/CODEOWNERS file with owners
• I have made corresponding changes to the system documentation if necessary

Original prompt

---

This section details on the original issue you should resolve

<issue_title>s</issue_title>
<issue_description>When a user wishes to run a CI case locally, they use the generate_workflows.sh script, which looks through the dev/ci/cases/pr directory for YAMLs to determine which cases to run (e.g. C96C48_ufs_hybatmDA.yaml). These cases are supported on different machines, denoted by the skip_ci_on_hosts key. However, when cases are run through GitLab, the supported cases are determined by the gitlab-ci-hosts.yaml YAML. Having this in two separate locations makes for a cumbersome update procedure when new test cases are added. These lists should be consolidated in some way and ideally in a centralized and clearly labeled and documented YAML that both generate_workflows.sh and GitLab can work with.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes s #47

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