use tsup to emit cjs

package.json

@@ -7,23 +7,28 @@
 	"exports": {
 		"./playwright": {
 			"types": "./dist/playwright.d.ts",
-			"import": "./dist/playwright.js"
+			"import": "./dist/playwright.js",
+			"require": "./dist/playwright.cjs"
 		},
 		"./types": {
 			"types": "./dist/types.d.ts",
-			"import": "./dist/types.js"
+			"import": "./dist/types.js",
+			"require": "./dist/types.cjs"
 		},
 		"./factory": {
 			"types": "./dist/factory.d.ts",
-			"import": "./dist/factory.js"
+			"import": "./dist/factory.js",
+			"require": "./dist/factory.cjs"
 		},
 		"./backend": {
 			"types": "./dist/backend.d.ts",
-			"import": "./dist/backend.js"
+			"import": "./dist/backend.js",
+			"require": "./dist/backend.cjs"
 		},
 		"./utils": {
 			"types": "./dist/utils.d.ts",
-			"import": "./dist/utils.js"
+			"import": "./dist/utils.js",
+			"require": "./dist/utils.cjs"
 		}
 	},
 	"type": "module",
@@ -41,7 +46,9 @@
 	"homepage": "https://github.com/ensdomains/headless-web3-provider#readme",
 	"scripts": {
 		"test": "playwright test",
-		"build": "tsc -p tsconfig.build.json",
+		"build:esm": "tsup",
+		"build:cjs": "tsup --config tsup.cjs.config.ts",
+		"build": "pnpm build:cjs && pnpm build:esm",
 		"check": "biome check",
 		"fmt": "biome format",
 		"lint": "biome lint"
@@ -55,6 +62,7 @@
 		"@playwright/test": "^1.45.1",
 		"@types/node": "^20.14.9",
 		"prool": "^0.0.15",
+		"tsup": "^8.2.4",
 		"tsx": "^4.16.2",
 		"typescript": "~5.5.4",
 		"viem": "^2.17.1"