fix(emacs): install emacsql via Nix

Recent versions of emacsql attempts to build emacsql-sqlite.c at
runtime. I'm not sure why, considering that its companion package,
emacsql-sqlite, builds the same code too.

But whatever the reason, it has to be moved over to Nix. Otherwise, an
entire C toolchain would have to be exposed to the user environment in
order to create an impure binary.

files/.config/doom/packages.el

@@ -17,6 +17,7 @@
 ;; These packages attempt to build native C code at runtime. Prefer copies
 ;; installed by Nix if they exist to avoid having to make GCC globally
 ;; available.
+(package! emacsql :built-in 'prefer)
 (package! emacsql-sqlite :built-in 'prefer)
 (package! pdf-tools :built-in 'prefer)
 

nix/home/modules/emacs.nix

@@ -19,6 +19,7 @@ in
       extraPackages = epkgs:
         with epkgs; [
           # include Doom Emacs dependencies that tries to build native C code
+          emacsql
           emacsql-sqlite
           pdf-tools
           vterm