Plugin Dependencies: Recognize network-active dependencies

[benitoalba]

Summary

wp_get_plugin_action_button() only checked the per-site active_plugins option when determining whether plugin dependencies were active. On multisite, this caused the Activate button to remain disabled when a dependency was network-active.

This changes the dependency check to use is_plugin_active(), which recognizes both per-site and network activation, and adds a multisite regression test.

Trac ticket: https://core.trac.wordpress.org/ticket/65759

Testing

• Focused multisite regression test: 1 test, 3 assertions
• Complete action-button test class on multisite: 3 tests, 7 assertions
• Complete action-button test class on single site: 3 tests, 6 assertions
• PHP coding standards on both changed files
• git diff --check

Use of AI Tools

AI assistance: Codex assisted with drafting the code and tests. I reviewed and validated the changes and completed the remaining contribution work.

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