Merge pull request #1050 from ember-cli/fix-release-plan

use package.json pnpm version for release-plan

Author: mansona

.github/workflows/plan-release.yml

@@ -53,8 +53,6 @@ jobs:
           fetch-depth: 0
           ref: 'main'
       - uses: pnpm/action-setup@v4
-        with:
-          version: 9
       - uses: actions/setup-node@v4
         with:
           node-version: 18

.github/workflows/publish.yml

@@ -47,8 +47,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: pnpm/action-setup@v4
-        with:
-          version: 9
       - uses: actions/setup-node@v4
         with:
           node-version: 18