Remove unused jest dependency

3bg/features/steps/concat.js

@@ -1,5 +1,5 @@
 import { Given, When, Then } from '@cucumber/cucumber'
-import { expect } from 'chai'
+import assert from 'node:assert/strict'
 
 Given('the start value is {string}', function (string) {
   this.concat = string
@@ -10,5 +10,5 @@ When('I concatenate {string}', function (string) {
 })
        
 Then('the result should be {string}', function (string) {
-  expect(string).to.equal(this.concat)
+  assert.equal(string, this.concat)
 })