kimai: fix bundled assets missing

We were relying on `composerNoScripts = false` to make sure post-install
command `assets:install` is run. `assets:install` copies assets from
`vendor/` directory into `public/` directory, placing it in appropriate
places.

However, with commit 80bb9aec24 ("kimai: switch to buildComposerProject2
and tag"), we switched to `buildComposerProject2` which has moved
`composer install` step to `composerVendor` derivation. By design,
`composerVendor` ignores anything that happens outside `vendor/`, so
the assets was not copied into final derivation.

So stop relying on `composerNoScripts = false` and run `assets:install`
ourselves in `postInstall` step. A side effect of this is that there is
another post-install step being skipped (`cache:clear`). However we
simply handle caches outside of the derivation (it's handled in the
module), so that's not a problem.

Fixes: https://github.com/NixOS/nixpkgs/issues/442208

nixos/tests/kimai.nix

@@ -17,5 +17,8 @@
     machine.wait_for_unit("nginx.service")
     machine.wait_for_open_port(80)
     machine.succeed("curl -v --location --fail http://localhost/")
+    # Make sure bundled assets are served.
+    # https://github.com/NixOS/nixpkgs/issues/442208
+    machine.succeed("curl -v --location --fail http://localhost/bundles/tabler/tabler.css")
   '';
 }

pkgs/by-name/ki/kimai/package.nix

@@ -41,13 +41,16 @@ php.buildComposerProject2 (finalAttrs: {
   vendorHash = "sha256-I4v4WkPGLc8vBPjCiYzPxcLn4rH3HWtQXSqwGVKXeGg=";
 
   composerNoPlugins = false;
-  composerNoScripts = false;
 
   postInstall = ''
     # Make available the console utility, as Kimai doesn't list this in
     # composer.json.
     mkdir -p "$out"/share/php/kimai "$out"/bin
     ln -s "$out"/share/php/kimai/bin/console "$out"/bin/console
+
+    # Install bundled assets. This is normally done in the `composer install`
+    # post-install script, but it's being skipped.
+    (cd "$out"/share/php/kimai && php ./bin/console assets:install)
   '';
 
   passthru.tests = {