Bump deps and migrate ESLINT to v9 (#2406)

eslint.config.mjs

@@ -0,0 +1,42 @@
+import globals from "globals";
+import js from "@eslint/js";
+import eslintPluginPrettierRecommended from "eslint-plugin-prettier/recommended";
+
+export default [
+	js.configs.recommended,
+	eslintPluginPrettierRecommended,
+
+	// Ignore machine-generated files
+	{
+		ignores: [
+			"packages/font-glyphs/**/*.mjs",
+			"packages/font-otl/**/*.mjs",
+			"packages/font/src/generated/ttfa-ranges.mjs", // Machine-generated
+		],
+	},
+
+	// Main monorepo
+	{
+		files: ["packages/*/src/**/*.mjs", "tools/*/src/**/*.mjs", "verdafile.mjs"],
+		languageOptions: {
+			ecmaVersion: 2022,
+			sourceType: "module",
+			globals: {
+				...globals.node,
+				...globals.nodeBuiltin,
+
+				...globals.es2021,
+			},
+		},
+
+		rules: {
+			semi: ["error", "always"],
+			"no-var": "error",
+			"no-console": 0,
+			"no-constant-condition": ["error", { checkLoops: false }],
+			"no-mixed-spaces-and-tabs": ["error", "smart-tabs"],
+			"no-unused-vars": ["off"],
+			complexity: ["warn", 16],
+		},
+	},
+];