Fix a comment about the permission issue of git

Dockerfile

@@ -4,7 +4,10 @@ FROM hashicorp/terraform:$TERRAFORM_VERSION AS terraform
 FROM golang:1.17.8-alpine3.15
 RUN apk --no-cache add make git bash curl jq
 
-# Fix a permission issue for CVE-2022-24765
+# A workaround for a permission issue of git.
+# Since UIDs are different between host and container,
+# the .git directory is untrusted by default.
+# We need to allow it explicitly.
 # https://github.com/actions/checkout/issues/760
 RUN git config --global --add safe.directory /work