Unity AI "Assistant" package are not visible and cannot be installed when using the Package Manager’s Unity Registry

How to reproduce:
1. Create a new project
2. Open the Package Manager (Window -> Asset Management -> Package Manager)
3. Open the "Unity Registry" tab
4. Type “Assistant” in the search field
5. Observe the Package Manager window

Expected result: The “Assistant” package appears in the search results
Actual result: The “Assistant” package does not appear in the search result

Reproducible with: 1.0.0-pre.8 (6000.2.0b1), 1.0.0-pre.12 (6000.2.13f1, 6000.3.0f1 (820bc0c5f094), 6000.4.0a5, 6000.5.0a1)
Could not test with: 2022.1.0a5, 6000.0.62f1, 6000.2.0a10 (Unity AI Assistant isn’t available)

Reproducible on: macOS 15.3.2 (24D81) (M1 Max)
Not reproducible on: No other environments tested

Notes:

• The "Assistant" package can be installed using its technical name