After updating to US 4.0.9 from the App Store, the UserScripts extension no longer appears in the extensions list in Safari. Launching the app says that the Safari Extension State is Unknown.

System Information:

macOS version: 12.1 (Intel)
Userscripts version: 4.0.9 (41)
Safari version: 15.2 (17612.3.6.1.6)
Is this issue related to script injection? No
Did the test script (pasted above) successfully run on your machine? N/A