chore: update devcontainer docker base image (#739)

Since nix uses a newer version of glibc, this matches it more closely (so proc macros don't have trouble generating)

.devcontainer/Dockerfile

@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/devcontainers/base:bullseye
+FROM mcr.microsoft.com/devcontainers/base:bookworm
 
 RUN apt-get update \
     && export DEBIAN_FRONTEND=noninteractive \