Build directories are not fully wiped on new build

[NickSdot]

Describe the Bug

Build directories are not fully wiped on new builds. This can lead to leftover files in build. Imagine this:

• Build A has a post typo.html
• You realise the typo, and rename the file to fixed.html
• Build B will have typo.html and fixed.html

Solution you'd like

Build subdirectories should be wiped on new builds.

Environment

• MacOS latest
• Nuekit version & JS runtime: Nue 1.0.0-RC.4 • Bun 1.2.19