test: label tests dir as having sideEffects=true

[ChALkeR]

This package is labelled as sideEffects=false:

noble-ed25519/package.json

Lines 10 to 14 in 0a2838f

	"type": "module",
	"main": "index.js",
	"module": "index.js",
	"types": "index.d.ts",
	"sideEffects": false,

That shouldn't apply to tests, because of:

1. This bare import:

   noble-ed25519/test/ed25519.webcrypto.test.js

   Line 5 in 0a2838f

   import './ed25519.test.js';

2. This setup (which is required):

   noble-ed25519/test/ed25519.helpers.js

   Line 8 in 0a2838f

   ed.etc.sha512Sync = (...m) => sha512(ed.etc.concatBytes(...m));

Adding sideEffects=true to the test dir makes tests suitable for running in bundled mode

To test:

• npm test
• CI
• npx @exodus/test (Node.js)
• npx @exodus/test --engine jsc:bundle --bundle-entropy-size=1000000 (JSC)
  Requires jsc available in PATH
• npx @exodus/test --engine hermes:bundle --bundle-entropy-size=1000000 (Hermes)
  Requires hermes available in PATH or https://npmjs.com/hermes-engine-cli installed with @exodus/test:
  npm add @exodus/test hermes-engine-cli

Refs: paulmillr/noble-curves#166