Script Plugins are not available as script roots outside of development environment

Steps to reproduce:
1. Create a script plugin with a class or script file in the src/main/resources directory. e.g. the ScratchScript.groovy file in scriptrunner-samples.
2. Build & install said plugin into your instance
3. Navigate to the script console's file tab
4. Type ScratchScr into the file blank

Expected behavior:
The path to the ScratchScript.groovy file should appear in the dropdown & be runnable from Script Console.

Actual behavior:
ScratchScript.groovy is not reachable, even after entering the full path (e.g. com/example/ScratchScript.groovy).