chore: migrate to eslint@9

eslint.config.mjs

@@ -0,0 +1,30 @@
+import bpmnIoPlugin from 'eslint-plugin-bpmn-io';
+
+export default [
+  {
+    ignore: [
+      'dist',
+      '.nyc_output',
+      'coverage'
+    ]
+  },
+  ...bpmnIoPlugin.configs.browser,
+  ...bpmnIoPlugin.configs.mocha.map(config => {
+    return {
+      ...config,
+      files: [
+        '**/test/**/*.js'
+      ]
+    };
+  }),
+  {
+    languageOptions: {
+      globals: {
+        sinon: true
+      },
+      files: [
+        '**/test/**/*.js'
+      ]
+    }
+  }
+];