Remove redundant clean step from CI workflows

The 'Clean DerivedData' step was removed from both ci.yml and ui_tests.yml workflows to streamline the build process and avoid unnecessary cleaning operations.

Author: gemcoder21

.github/workflows/ci.yml

@@ -74,9 +74,6 @@ jobs:
       - name: Build Core
         run: just generate-stone
 
-      - name: Clean DerivedData
-        run: just clean
-
       - name: Build for Testing
         run: just build-for-testing
 

.github/workflows/ui_tests.yml

@@ -71,9 +71,6 @@ jobs:
 
       - name: Install dependencies
         run: just install-toolchains
-      
-      - name: Clean DerivedData
-        run: just clean
 
       - name: Build Core
         run: just generate-stone