⬆️ Update BookStackApp/BookStack to v23.08.2 (#253)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

bookstack/Dockerfile

@@ -6,7 +6,7 @@ FROM ${BUILD_FROM}
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
 # Setup base
-ARG BOOKSTACK_VERSION="v23.06.2"
+ARG BOOKSTACK_VERSION="v23.08.2"
 # hadolint ignore=DL3003
 RUN \
     apk add --no-cache \