buld(nix): Misc Nix-related improvements

- Nixpkgs 23.11 is deprecated, use 24.05 instead
- update flake.lock
- add glibc as a build dependency
- add doxygen and graphviz as development dependencies for `make format`

flake.nix

@@ -2,7 +2,7 @@
   description = "Tilde Friends is a platform for making, running, and sharing web applications.";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
     flake-utils.url = "github:numtide/flake-utils";
   };
 
@@ -31,6 +31,8 @@
             openssl
             llvmPackages_17.clang-unwrapped
             unzip
+            doxygen
+            graphviz
           ];
         };
       });