fix clang-format installation (#129)

the dev image had broken because clang-format-18 was no longer available. switching to
bookworm and a different dist to remain with stable v18

docker/Dockerfile.debian

@@ -1,4 +1,4 @@
-FROM debian:bullseye-slim
+FROM debian:bookworm-slim
 WORKDIR /usr/src
 
 #clang-format, gdb, valgrind
@@ -7,8 +7,8 @@ RUN apt-get update \
     curl \
     gnupg2 \
   && curl -fsSL https://apt.llvm.org/llvm-snapshot.gpg.key | tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc \
-  && echo "deb http://apt.llvm.org/bullseye/ llvm-toolchain-bullseye main" >> /etc/apt/sources.list \
-  && echo "deb-src http://apt.llvm.org/bullseye/ llvm-toolchain-bullseye main" >> /etc/apt/sources.list \
+  && echo "deb http://apt.llvm.org/bookworm/ llvm-toolchain-bookworm-18 main" >> /etc/apt/sources.list \
+  && echo "deb-src http://apt.llvm.org/bookworm/ llvm-toolchain-bookworm-18 main" >> /etc/apt/sources.list \
   && apt-get update \
   && apt-get install -y \
     clang-format-18 \