core: bump node from 18 to 20 (#5329)

* core: bump node from 18 to 20

Bumps node from 18 to 20.

---
updated-dependencies:
- dependency-name: node
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

* bump node everywhere, fixup go ci

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

* bump versions in docs

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

---------

Signed-off-by: dependabot[bot] <support@github.com>
Signed-off-by: Jens Langhammer <jens@goauthentik.io>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Jens Langhammer <jens@goauthentik.io>

website/developer-docs/setup/frontend-dev-environment.md

@@ -6,12 +6,12 @@ If you want to only make changes on the UI, you don't need a backend running fro
 
 ### Prerequisites
 
--   Node (any recent version should work, we use 18.x to build)
+-   Node (any recent version should work, we use 20.x to build)
 -   Make (again, any recent version should work)
 -   Docker and docker-compose
 
 :::info
-Depending on platform, some native dependencies might be required. On macOS, run `brew install node@18`, and for docker `brew install --cask docker`
+Depending on platform, some native dependencies might be required. On macOS, run `brew install node@20`, and for docker `brew install --cask docker`
 :::
 
 ### Instructions