Build inside umf dir

Author: EuphoricThinking

.github/workflows/reusable_benchmarks.yml

@@ -26,8 +26,8 @@ permissions:
   pull-requests: write
 
 env:
-  BUILD_DIR : "${{github.workspace}}/build"
   UMF_DIR: "${{github.workspace}}/umf-repo"
+  BUILD_DIR : "${{github.workspace}}/umf-repo/build"
   # INSTL_DIR : "${{github.workspace}}/../install-dir"
 
 jobs: