Added topic 'magisk'

[DerGoogler]

Please confirm this pull request meets the following requirements:

• I followed the contributing guidelines: https://github.com/github/explore/blob/main/CONTRIBUTING.md.
• I am not the sole author or employee of a company who created either the topic I am modifying/adding or the collection entry I am modifying/adding.

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• Curating a new topic or collection
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Curating a new topic or collection

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This PR adds the 'Magisk' topic to highlight its significance as a popular Android rooting tool with systemless modification capabilities

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