Reproduction steps:
1. Open the user's attached "AssetDatabaseRefreshBug.zip" project
2. Open the Profiler window and switch to Editor profiling
3. Select "UniversalRP-HighQuality" asset in the Settings folder
4. Change Lighting or Shadows settings (e.g. Main Light, Soft Shadows, etc) in the Inspector
5. Open the NewUnlitShader and make any change (e.g change LOD from 100 to 1000)
6. Open the Editor and note the CPU spike in the Profiler window
7. Repeat steps 3-6 a few more times (~3-10) and observe the Profiler

Expected result: Shader.CompileGPUProgram execution time does not change
Actual result: Shader.CompileGPUProgram execution time increases

Reproducible with: 2020.3.12f1, 2021.1.11f1, 2021.2.0a15
Not reproducible with: 2021.2.0a16 (<100ms), 2021.2.0a19
Could not test with: 2018.4, 2019.4 (project breaks on downgrade)

Notes:
- the execution time increases inconsistently, it might only increase only after every 5 or 10 attempts
- an example of how fast it can increase in 2021.1.10f1 (ms): 85, 283, 353, 330, 355, 340, 341, 436, 550, 670, 671