fix: do not transform exponentiation operator (#96)

The `babel-plugin-transform-exponentiation-operator ` Babel plugin transforms `1n ** 1n` into `Math.pow(1n, 1n)` which doesn't work because `Math.pow` doesn't support BigInts - facebook/create-react-app#6907 (comment)

This is used in `@noble/ed25519` which recently got added to `libp2p-crypto` - libp2p/js-libp2p-crypto#202

The fix is to change the `"browsersList"` setting to exclude ie and old android - hirosystems/stacks.js#1096 (comment)

package.json

@@ -15,6 +15,8 @@
   "browserslist": {
     "production": [
       ">0.2%",
+      "not ie <= 99",
+      "not android <= 4.4.4",
       "not dead",
       "not op_mini all"
     ],