Update cmake-multi-platform.yml

Fixing incomplete line

Author: PapeCoding

.github/workflows/cmake-multi-platform.yml

@@ -67,4 +67,4 @@ jobs:
 
     - name: Build
       # Build your program with the given configuration. Note that --config is needed because the default Windows generator is a multi-config generator (Visual Studio generator).
-      run: cmake --build ${{ steps.st
+      run: cmake --build ${{ steps.strings.outputs.build-output-dir }} --config ${{ matrix.build_type }}