build(deps-dev): bump @types/nodemailer from 7.0.11 to 8.0.0 in /backend

Bumps [@types/nodemailer](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/nodemailer) from 7.0.11 to 8.0.0.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/nodemailer)

---
updated-dependencies:
- dependency-name: "@types/nodemailer"
  dependency-version: 8.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Daniel Volz <mail@danielvolz.org>

backend/package-lock.json

@@ -32,7 +32,7 @@
       "devDependencies": {
         "@biomejs/biome": "^2.4.10",
         "@types/node": "^25.5.2",
-        "@types/nodemailer": "^7.0.11",
+        "@types/nodemailer": "^8.0.0",
         "@types/supertest": "^7.2.0",
         "@vitest/coverage-v8": "^4.1.2",
         "drizzle-kit": "^0.31.10",
@@ -2637,9 +2637,9 @@
       }
     },
     "node_modules/@types/nodemailer": {
-      "version": "7.0.11",
-      "resolved": "https://registry.npmjs.org/@types/nodemailer/-/nodemailer-7.0.11.tgz",
-      "integrity": "sha512-E+U4RzR2dKrx+u3N4DlsmLaDC6mMZOM/TPROxA0UAPiTgI0y4CEFBmZE+coGWTjakDriRsXG368lNk1u9Q0a2g==",
+      "version": "8.0.0",
+      "resolved": "https://registry.npmjs.org/@types/nodemailer/-/nodemailer-8.0.0.tgz",
+      "integrity": "sha512-fyf8jWULsCo0d0BuoQ75i6IeoHs47qcqxWc7yUdUcV0pOZGjUTTOvwdG1PRXUDqN/8A64yQdQdnA2pZgcdi+cA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {

backend/package.json

@@ -41,7 +41,7 @@
   "devDependencies": {
     "@biomejs/biome": "^2.4.10",
     "@types/node": "^25.5.2",
-    "@types/nodemailer": "^7.0.11",
+    "@types/nodemailer": "^8.0.0",
     "@types/supertest": "^7.2.0",
     "@vitest/coverage-v8": "^4.1.2",
     "drizzle-kit": "^0.31.10",