CI: Use macos-14 for GMT Dev Tests workflow

[weiji14]

Description of proposed changes

Use macos-14 (Sonoma) instead of macos-13 (Ventura) in the "GMT Dev Tests" workflow, available since 30 Jan 2024. Note that this uses the M1 Chips!

After merging this PR, we will have tests on 3 versions of macOS:

• macos-11 Big Sur - used in ci_tests_legacy.yaml
• macos-13/macos-latest Ventura - used in most of our ci_*.yml files
• macos-14 Sonoma - used in ci_tests_dev.yaml

Should we also change ci_tests_legacy.yaml to use macos-12 instead of macos-11? It seems like they marked macos-11 as deprecated in actions/runner-images#9252, but we can probably use it for a while longer.

References:

• https://github.blog/changelog/2024-01-30-github-actions-macos-14-sonoma-is-now-available
• https://github.blog/changelog/2024-01-30-github-actions-introducing-the-new-m1-macos-runner-available-to-open-source
• https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories

Supersedes #2516

Reminders

• Run make format and make check to make sure the code follows the style guide.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Add new public functions/methods/classes to doc/api/index.rst.
• Write detailed docstrings for all functions/methods.
• If wrapping a new module, open a 'Wrap new GMT module' issue and submit reasonably-sized PRs.
• If adding new functionality, add an example to docstrings or tutorials.
• Use underscores (not hyphens) in names of Python files and directories.

Slash Commands

You can write slash commands (/command) in the first line of a comment to perform
specific operations. Supported slash command is:

• /format: automatically format and lint the code

[seisman]

Looks good. There are 3 failing x2sys_cross tests, which are more likely due to upstream issues.