Fix Debian build

build/docker/debian.Dockerfile

@@ -111,7 +111,7 @@ RUN dotnet --version
 RUN apt update -y && \
     apt install -t unstable lsb-release apt-transport-https ca-certificates software-properties-common -y && \
     curl -o /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg && \
-    sh -c 'echo "deb https://packages.sury.org/php/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/php.list' && \
+    sh -c 'echo "deb https://packages.sury.org/php/ bookworm main" > /etc/apt/sources.list.d/php.list' && \
     apt -y clean && rm -rf /var/lib/apt/lists/*
 
 RUN apt -y update && apt -y install \