nix: fix up builds

it seems latest nixpkgs broke sqlite-lib builds. the static pkg set does
not provide ranlib or ar anymore.

Signed-off-by: oppiliappan <[e-mail]>

flake.nix

···
           }).buildGoApplication;
         modules = ./nix/gomod2nix.toml;
         sqlite-lib = self.callPackage ./nix/pkgs/sqlite-lib.nix {
-          inherit (pkgs) gcc;
           inherit sqlite-lib-src;
         };
         lexgen = self.callPackage ./nix/pkgs/lexgen.nix {inherit indigo;};

nix/pkgs/sqlite-lib.nix

···
 {
-  gcc,
   stdenv,
   sqlite-lib-src,
 }:
 stdenv.mkDerivation {
   name = "sqlite-lib";
   src = sqlite-lib-src;
-  nativeBuildInputs = [gcc];
+
   buildPhase = ''
-    gcc -c sqlite3.c
-    ar rcs libsqlite3.a sqlite3.o
-    ranlib libsqlite3.a
+    $CC -c sqlite3.c
+    $AR rcs libsqlite3.a sqlite3.o
+    $RANLIB libsqlite3.a
+  '';
+
+  installPhase = ''
     mkdir -p $out/include $out/lib
     cp *.h $out/include
     cp libsqlite3.a $out/lib