chore(package): specify PNPM version in package.json and update release workflow to use PNPM 9.15.0

Author: Ansonhkg

.github/workflows/release.yml

@@ -23,6 +23,8 @@ jobs:
 
       - name: Setup PNPM
         uses: pnpm/action-setup@v4
+        with:
+          version: 9.15.0
 
       - name: Install Dependencies
         run: pnpm install --frozen-lockfile

package.json

@@ -2,6 +2,7 @@
   "name": "@lit-protocol/js-sdk",
   "version": "0.0.1",
   "license": "MIT",
+  "packageManager": "[email protected]",
   "scripts": {
     "reset": "rimraf dist pnpm-lock.yaml node_modules tmp yarn-error.log yarn.lock package-lock.json learn-debug.log .nx lit-auth-storage pkp-tokens lit-auth-local ./e2e/dist ./e2e/node_modules",
     "build": "nx run-many --parallel=false --target=build --all --exclude=wrapped-keys,wrapped-keys-lit-actions",