Update to pnpm 8, fix lockfile

Renovate PRs were all failing on initial install step, hope this will fix it.

.github/actions/pnpm/action.yml

@@ -1,22 +1,16 @@
 name: Setup node and pnpm
 description: Setup node and install dependencies using pnpm
 runs:
-  using: "composite"
+  using: 'composite'
   steps:
     - uses: pnpm/[email protected]
       with:
-        version: 7
+        version: 8.6.5
     - uses: actions/setup-node@v3
       with:
         cache: 'pnpm'
     - name: 'Install dependencies'
       shell: 'bash'
       run: |
         pnpm -v
-        pnpm install --fix-lockfile
-        git_diff=$(git diff)
-        if [[ "$git_diff" -eq "" ]]; then
-          echo "Success: no lockfile differences" ;
-        else
-          echo "Error: lockfile differences detected";
-        fi
+        pnpm install

.npmrc

@@ -0,0 +1 @@
+auto-install-peers=false

package.json

@@ -51,6 +51,6 @@
   },
   "volta": {
     "node": "18.16.0",
-    "pnpm": "7.33.0"
+    "pnpm": "8.6.5"
   }
 }