Docs: add Odyssey and WAL-G to Ecosystem section

[tuhaihe]

Add two new ecosystem projects to the documentation:

• Odyssey (Connection Pooling): starting from v1.5.1, Odyssey introduces native support for Apache Cloudberry.
• WAL-G (Backup & Restore): starting from v3.0.5, WAL-G introduces native support for Apache Cloudberry.

closes: #ISSUE_Number

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[leborchuk]

LGTM, checked products release notes - it mentions Cloudberry, all Ok