Update nginxinc/nginx-unprivileged:alpine-slim Docker digest to a6bec37 (#31473)

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

Author: renovate[bot]

Dockerfile

@@ -19,7 +19,7 @@ RUN /src/scripts/docker-package.sh
 RUN cp /src/config.sample.json /src/webapp/config.json
 
 # App
-FROM nginxinc/nginx-unprivileged:alpine-slim@sha256:8e23ab31c214ee1d7f832d63b2ee768d5cbc270a94a2cba0752fed93ad83e345
+FROM nginxinc/nginx-unprivileged:alpine-slim@sha256:a6bec37058b9047ece799c01d98dc6d5aa0542b6583cc69f187652f91331a752
 
 # Need root user to install packages & manipulate the usr directory
 USER root