Upgrade to Foundry v7 (#2406)

.changeset/empty-camels-explode.md

@@ -0,0 +1,5 @@
+---
+'@sumup/stylelint-plugin-circuit-ui': major
+---
+
+Upgraded to [Stylelint 16](https://stylelint.io/migration-guide/to-16/#removed-support-for-nodejs-less-than-18120) and migrated to ECMAScript modules (ESM). The minimum required Node.js version is 18.12.0.

.eslintignore

@@ -7,6 +7,8 @@ public/
 __coverage__/
 __reports__/
 *.config.*
+package.json
+package-lock.json
 *rc.*
 /scripts/
 # disable linting for templates because it will have its own rules when used in a new app

.eslintrc.js

@@ -25,6 +25,20 @@ module.exports = require('@sumup/foundry/eslint')({
     tsconfigRootDir: __dirname,
   },
   overrides: [
+    {
+      files: [
+        '**/*.spec.*',
+        '**/jest*',
+        '**/setupTests.*',
+        '**/test-utils.*',
+        '**/*Fixtures.*',
+        '**/__fixtures__/**/*',
+        '**/__mocks__/**/*',
+      ],
+      rules: {
+        'testing-library/no-container': 'warn',
+      },
+    },
     {
       files: ['**/*.stories.*'],
       rules: {