fix: downgrade pnpm to v8 (#199)

Author: kormide

.github/workflows/ci.yaml

@@ -16,11 +16,11 @@ jobs:
       - uses: actions/checkout@v4
       - uses: pnpm/action-setup@v4
         with:
-          version: 9
+          version: 8
           run_install: false
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           cache: pnpm
       - run: pnpm install --frozen-lockfile
       - run: pnpm run build
@@ -36,11 +36,11 @@ jobs:
       - uses: actions/checkout@v4
       - uses: pnpm/action-setup@v4
         with:
-          version: 9
+          version: 8
           run_install: false
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           cache: pnpm
       # Setup gcloud application default credentials. While the credentials are not actually
       # used because Google api services are stubbed, instantiating any of the Google node

package.json

@@ -5,7 +5,7 @@
   "main": "./application/webhook/index.js",
   "engines": {
     "node": "^20",
-    "pnpm": ">=9"
+    "pnpm": "^8"
   },
   "scripts": {
     "prebuild": "node tools/clean-dist-files.js",