Remove node 16 from tests and stages in CI

[zatteo]

Transition to node 20 has been done successfuly on our production servers.

### ✨ Features

*

### 🐛 Bug Fixes

*

### 🔧 Tech

* Remove node 16 from tests in CI
* Remove stages in CI

[bundlemon[bot]]

BundleMon

Unchanged files (4)

Status | Path | Size | Limits :------------: | ------------ | :------------: | :------------: :white_check_mark: | vendors/coachco2.(hash).js
| 1.72MB | - :white_check_mark: | app/coachco2.(hash).js
| 69.86KB | - :white_check_mark: | vendors-coachco2.(hash).(hash).min.css
| 36.61KB | - :white_check_mark: | app-coachco2.(hash).min.css
| 356B | -

No change in files bundle size

Final result: :white_check_mark:

View report in BundleMon website ➡️

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Current branch size history | Target branch size history