update: 2025.12.1 -> 2025.12.3

Closes #90

ChangeLogs:
* https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.2
* https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.3

Using the `client-go` library that is vendored in this release's `go.mod`
breaks all outposts for me, so we're now doing what upstream is also
doing, i.e. generating the Go client code ourselves.

components/client-go.nix

@@ -0,0 +1,20 @@
+{
+  authentik-src,
+  authentik-go,
+  openapi-generator-cli,
+  runCommand,
+}:
+
+runCommand "go-client-code" {
+  nativeBuildInputs = [
+    openapi-generator-cli
+  ];
+} ''
+  cp --no-preserve=mode -vr ${authentik-go}/ $out/
+  cp -vr ${authentik-src}/schema.yml $out/
+  pushd $out &>/dev/null
+    substituteInPlace config.yaml \
+      --replace-fail "templateDir: /local/templates/" "templateDir: ./templates/"
+    openapi-generator-cli generate -i schema.yml -g go -o . -c config.yaml
+  popd &>/dev/null
+''