chore(deps): update dunglas/frankenphp:latest docker digest to 8ac21b7

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

Author: renovate[bot]

Dockerfile

@@ -17,7 +17,7 @@ RUN composer install \
     --ignore-platform-reqs
 
 # Stage 2: Final image
-FROM dunglas/frankenphp:latest@sha256:145db7730bcbcfe0bfa2fe5d5953fc83919aa704807268e39b1a215e00d68a20
+FROM dunglas/frankenphp:latest@sha256:8ac21b7646f6ed7c8028cf518c95d318d0b5ea5235e76ff413b953e2eaff1bbd
 
 # Disable HTTPS by default for the container
 ENV SERVER_NAME=:80