NET_STANDARD_2_1, NET_STANDARD_2_0 are not defined when asmdef targets Editor only

Reproduction steps:
1. Open the attached project “IN-6270.zip”
2. Enter Play Mode
3. Exit Play Mode
4. Observe Console Window
5. In the Project Window, Click “Assets/Test.asmdef”
6. In the Inspector window, under Platforms click “Deselect all”
7. Check only “Editor”
8. Enter Play Mode
9. Observe Console Window

Expected result: NET_STANDARD_2_1, NET_STANDARD_2_0 are defined and script files compile
Actual result: NET_STANDARD_2_1, NET_STANDARD_2_0 are not defined and script files do not compile

Reproducible with: 2020.3.38f1, 2021.3.8f1, 2022.1.14f1, 2022.2.0b6, 2023.1.0a9

Reproducible on: Windows 10 Pro 21H2