ci: Use {{runner.temp}}

Otherwise, we risk multiple jobs using the same directory.

.github/workflows/ci.yaml

@@ -4,6 +4,7 @@ on:
     branches:
       - main
       - update_flake_lock_action
+      - ci/**
   pull_request:
 jobs:
   nix:
@@ -25,21 +26,23 @@ jobs:
       - name: NixOS test
         if: matrix.system == 'x86_64-linux'
         run: |
-          om init .#nixos -o /tmp/nixconfig \
+          CONF=${{ runner.temp }}/nixos && mkdir $CONF
+          om init .#nixos -o $CONF \
             --non-interactive \
             --params '{"hostname": "example", "username": "srid", "git-name": "Srid", "git-email": "[email protected]"}'
           set -x
-          nix build /tmp/nixconfig#nixosConfigurations.example.config.system.build.toplevel
+          nix build ${CONF}#nixosConfigurations.example.config.system.build.toplevel
           type -f ./result/etc/profiles/per-user/srid/bin/git
 
       - name: nix-darwin test
         if: matrix.system == 'aarch64-darwin' || matrix.system == 'x86_64-darwin'
         run: |
-          om init .#darwin -o /tmp/nixconfig \
+          CONF=${{ runner.temp }}/darwin && mkdir $CONF
+          om init .#darwin -o $CONF \
             --non-interactive \
             --params '{"hostname": "example", "username": "srid", "git-name": "Srid", "git-email": "[email protected]"}'
           set -x
-          nix build /tmp/nixconfig#darwinConfigurations.example.config.system.build.toplevel
+          nix build ${CONF}#darwinConfigurations.example.config.system.build.toplevel
           type -f ./result/etc/profiles/per-user/srid/bin/git
 
       # TODO: Use `om init` like above

modules/flake-parts/test.nix

@@ -11,6 +11,7 @@
           findutils
           gnugrep
         ];
+        # FIXME: This should use `{{ runner.temp }}` from ci.yaml
         text = ''
           set -x
           # Override the home directory to a temp location