feat(nix): Filter projects that should be built by CI

Instead of specifying CI projects manually, this filters them to move
the CI configuration into the derivations `meta` attributes.

tools/blog_cli/default.nix

@@ -5,4 +5,6 @@ pkgs.buildGoPackage {
   goPackagePath = "github.com/tazjin/personal/blog_cli";
   src = ./.;
   goDeps = ./deps.nix;
+
+  meta.enableCI = true;
 }

tools/kms_pass.nix

@@ -9,7 +9,7 @@
 { pkgs, kms, ... }:
 
 let inherit (pkgs) google-cloud-sdk tree writeShellScriptBin;
-in writeShellScriptBin "pass" ''
+in (writeShellScriptBin "pass" ''
   set -eo pipefail
 
   CMD="$1"
@@ -57,4 +57,4 @@ in writeShellScriptBin "pass" ''
       exit 1
       ;;
   esac
-''
+'') // { meta.enableCI = true; }