To reproduce:
1. Create a project in Unity 2021 (any release that supports URP 11)
2. Import package: Lost Crypt from the asset store: https://assetstore.unity.com/packages/essentials/tutorial-projects/lost-crypt-2d-sample-project-158673
3. In Package Manager, make sure to upgrade the URP version to 11
4. Observe the scene / game window

Expected: project is compatible with URP 11
Actual: shaders are broken resulting in most object in the scene being pink

Reproduced in URP package: 11
Not reproduced in URP package: 10.3.1

Note1: users also seem to confirm this behaviour in Lost Crypt's Asset store page. Not solvable by upgrading the materials.
Note2: the project indicates in the console that shaders failed to upgrade. Sample log:

"Material_Trees_3_Unlit material was not upgraded. There's no upgrader to convert Shader Graphs/ShaderGraph_Background_Unlit shader to selected pipeline
UnityEditor.Rendering.Universal.UniversalRenderPipelineMaterialUpgrader:UpgradeProjectMaterials () (at "