Fix CI pack source path: use /workspace instead of mission folder name

The git repo root IS the mission folder. actions/checkout puts files
directly in the workspace, so there's no subdirectory matching the
mission folder name. Use /workspace (the container mount point) as
the pack source.

.gitea/workflows/build.yml

@@ -23,7 +23,7 @@ jobs:
             -w /workspace \
             arwynfr/armake2:debian \
             pack \
-            "CTI 34 KP Liberation v0.96.7a Ruha.ruha" \
+            /workspace \
             "${{ env.PBO_NAME }}"
 
       - name: Verify PBO integrity