fix(ci): drop hardcoded pnpm version 10, defer to packageManager

The publish job checks out etherpad-lite core first (pinned to
pnpm@11 via packageManager); pnpm/action-setup@v6 then errors with
'Multiple versions of pnpm specified' because the workflow's version: 10
clashes with the checked-out repo's packageManager.

Removing 'version:' lets action-setup take pnpm@11 from packageManager,
which is what we actually want for compatibility with the rest of the
plugin ecosystem and what the test job already does.

Author: JohnMcLear

.github/workflows/npmpublish.yml

@@ -34,7 +34,10 @@ jobs:
       - uses: pnpm/action-setup@v6
         name: Install pnpm
         with:
-          version: 10
+          # No `version:` here — defer to packageManager in package.json so
+          # we don't get the "Multiple versions of pnpm specified" error
+          # when an upstream checkout (etherpad-lite) pins a different
+          # pnpm via packageManager. See pnpm/action-setup#225.
           run_install: false
       - name: Get pnpm store directory
         shell: bash

.github/workflows/test-and-release.yml

@@ -15,7 +15,7 @@ jobs:
           node-version: 20
       - uses: pnpm/action-setup@v6
         with:
-          version: 10
+          # No `version:` — defer to packageManager in package.json.
           run_install: false
       - name: Get pnpm store directory
         shell: bash