Unclearable obsolete errors are thrown preventing entering Play Mode or building the project when the AI packages are installed

Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Enable the AI customizable toolbar button (Customizable toolbar settings > Services > AI)
3. Click the customizable toolbar's AI button
4. Click the "Agree and install Unity AI"
5. Observe the Console window

Actual results: A lot of obsolete errors are thrown 

Expected results: No errors are thrown

Reproducible with versions: 6000.5.0b1 (c1f81ff5b082)

Not reproducible with versions: 6000.0.71f1, 6000.3.11f1, 6000.4.1f1, 6000.5.0a9 (acc4c1f79cd5), 6000.6.0a1

Tested on (OS): MacOS Silicon Tahoe 26.3, Ubuntu 24.04

Notes:

• Prevents entering Play Mode or building the project
• Seems to reproduce on all Assistant package versions, regressed from the Editor version rather than the package version