Old PBOs don't get cleaned

[jonpas]

HEMTT Version: 0.6.2 (dev 09c0902cc3fce1305a99b4544ffaab122ed80e15) Project: https://github.com/Theseus-Aegis/TheseusServices/commit/cf1285abbea17bf7068622f6a9c401c31e3357c7

Description:

Old built PBOs of removed folders in addons (probably not from optionals either) folder do not get cleaned out. This happens with build -f, clean and build --release -f.

Steps to reproduce:

• Build mod
• Remove one of the folders
• Build mod
• Observe old PBO stays there

Additional information:

N/A

HEMTT Output:

It correctly shows what it does.

[BrettMayson]

Duplicate of #58, I will mark the other one as a bug