fix: fixup blackduck scan job

.github/workflows/blackduck_scan_scheduled.yaml

@@ -25,6 +25,11 @@ jobs:
           go-version-file: '${{ github.workspace }}/go.mod'
           cache: false
 
+      - name: Get go environment for use with cache
+        if: matrix.build-mode == 'manual'
+        run: |
+          echo "go_cache=$(go env GOCACHE)" >> $GITHUB_ENV
+          echo "go_modcache=$(go env GOMODCACHE)" >> $GITHUB_ENV
       # This step will only reuse the go mod and build cache from main made during the Build,
       # see push_ocm.yaml => "ocm-cli-latest" Job
       # This means it never caches by itself and PRs cannot cause cache pollution / thrashing