How to reproduce:
1. Open the attached project named "MemoryLeakSRP"
2. Open Profiler window, on the Memory section, select Detailed
3. In the Project window open the Settings folder and select the ForwardRenderer asset
4. In the Profiler window, Click "Take Sample Playmode"
5. Observe the number of entries in the "Not Saved" -> "MonoBehaviour" category
6. In the Project window select and deselect the ForwardRenderer asset a couple of times
7. In the Profiler window, Click "Take Sample Playmode" again
8. Observe the number of entries and objects under "Not Saved" -> "MonoBehaviour"

Expected result: There are no duplicate objects that would indicate a memory leak
Actual result: Endless copies of UnityEditor.Rendering.Universal.ScriptableRendererFeatureEditor can be found suggesting a memory leak

Reproducible with: 7.3.1(2019.3.2f1), 7.5.1(2019.4.14f1), 8.2.0(2020.1.13f1), 10.1.0(2020.2.0b11), 11.0.0(2021.1.0a5)
Not reproducible with: 7.2.1(2019.3.2f1)
Could not test with: 2018.4.27f1(URP was not yet available)

Notes:
1. Steps 4 to 8 can be repeated multiple times to illustrate the continuous increase of objects under the MonoBehaviour behavior section. These objects are only cleared if the project is restarted