chore(login): migrate nextjs login to monorepo (#10134)

# Which Problems Are Solved

We move the login code to the zitadel repo.

# How the Problems Are Solved

The login repo is added to ./login as a git subtree pulled from the
dockerize-ci branch.
Apart from the login code, this PR contains the changes from #10116

# Additional Context

- Closes https://github.com/zitadel/typescript/issues/474
- Also merges #10116  
- Merging is blocked by failing check because of:
- https://github.com/zitadel/zitadel/pull/10134#issuecomment-3012086106

---------

Co-authored-by: Max Peintner <peintnerm@gmail.com>
Co-authored-by: Max Peintner <max@caos.ch>
Co-authored-by: Florian Forster <florian@zitadel.com>

.github/dependabot.yml

@@ -22,6 +22,19 @@ updates:
   commit-message:
     prefix: chore
     include: scope
+- package-ecosystem: npm
+  directory: '/login'
+  open-pull-requests-limit: 3
+  schedule:
+    interval: daily
+  groups:
+    prod:
+      dependency-type: production
+    dev:
+      dependency-type: development
+  ignore:
+    - dependency-name: "eslint"
+      versions: [ "9.x" ]
 - package-ecosystem: gomod
   groups:
     go: