[CI] Fixed composer cache for code blocks job

Author: Nyholm

.github/workflows/ci.yaml

@@ -127,6 +127,7 @@ jobs:
 
           - name: Get composer cache directory
             id: composercache
+            working-directory: _build
             run: echo "::set-output name=dir::$(composer config cache-files-dir)"
 
           - name: Cache dependencies