fix(sbom): manage separate GitLab cache to prevent permission denied error

closes #26

templates/gitlab-ci-golang.yml

@@ -511,6 +511,12 @@ go-sbom:
   image:
     name: $GO_SBOM_IMAGE
     entrypoint: [""]
+  # manage separate GitLab cache to prevent permission denied error (this image being rootless, it can't rewrite Go cache - owned by root)
+  # see: https://gitlab.com/gitlab-org/gitlab-runner/-/issues/29663
+  cache:
+    key: "$CI_COMMIT_REF_SLUG-golang-sbom"
+    paths:
+      - $GO_PROJECT_DIR/.cache/
   # force no dependency
   dependencies: []
   needs: []