feat: [OCA-1639] - Add Gemma3, Qwen, Milvus, pgvector, and GPT-oss Markeplace apps (#13420)

* add marketpalce apps feb

* add categories for mern & plex

* Added changeset: Add Gemma3, Qwen, Milvus, pgvector, and GPT-oss Markeplace apps

Author: hmorris3293

packages/manager/.changeset/pr-13420-added-1771523317072.md

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+---
+"@linode/manager": Added
+---
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+Add Gemma3, Qwen, Milvus, pgvector, and GPT-oss Markeplace apps ([#13420](https://github.com/linode/manager/pull/13420))