fix: z-align grid lines

[markov00]

Summary

Details

Issues

Checklist

• [ ] The proper chart type label has been added (e.g. :xy, :partition)
• [ ] The proper feature labels have been added (e.g. :interactions, :axis)
• [ ] The :theme label has been added and the @elastic/eui-team team has been pinged when there are Theme API changes
• [ ] All related issues have been linked (i.e. closes #123, fixes #123)
• [ ] New public API exports have been added to packages/charts/src/index.ts
• [ ] Unit tests have been added or updated to match the most common scenarios
• [ ] The proper documentation and/or storybook story has been added or updated
• [ ] The code has been checked for cross-browser compatibility (Chrome, Firefox, Safari, Edge)
• [ ] Visual changes have been tested with all available themes including dark, light, eui-dark & eui-light

[elastic-datavis[bot]]

✅ Successful Deployment - 9fdbf162ea79b4cb1101837c13d5ca456434319f

• Storybook
• e2e server
• Playwright report