fix rgb_matrix pixel fractal bug

[jiaxin96]

Description

Under the rgb matrix PIXEL_FRACTAL effect , skip the invalid NO_LED to solve the key failure when LTO_ENABLE is turned on and other possible problems after in some arm keyboards.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[jiaxin96]

This fix-pr should not affect the helix/rev3_5rows keyboard, please check. @drashna @fauxpark

[github-actions]

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