Update nginxinc/nginx-unprivileged Docker tag to v1.26.3

Author: renovate-bot

Dockerfile

@@ -16,6 +16,6 @@ RUN set -ex; \
     npx grunt prod; \
     rm /tmp/cyberchef/build/prod/BundleAnalyzerReport.html /tmp/cyberchef/build/prod/CyberChef_$CYBERCHEF_VERSION.zip;
 
-FROM nginxinc/nginx-unprivileged:1.26.2@sha256:3c216da7d3aa0384782e1199a7b30c8d3bc4b0288dcac32c178b0c0fb26f8059
+FROM nginxinc/nginx-unprivileged:1.26.3@sha256:7ca5215ddc4384f5062458082944915ff23725efe0dae206b62e7e9a31b331fc
 COPY --from=build /tmp/cyberchef/build/prod /usr/share/nginx/html
 EXPOSE 8080