Update set-output syntax (#5430)

Summary:
This will otherwise break soon.

Closes #5430.

Redone using the instructions from here: https://github.com/actions/cache/blob/main/examples.md#node---yarn

Pull Request resolved: #5658

Test Plan: Green CI

Reviewed By: antonk52

Differential Revision: D59962261

Pulled By: passy

fbshipit-source-id: 1d3cfaf69c9e79195e71f3c07bf946319f3bcbce

.github/workflows/nodejs.yml

@@ -20,7 +20,8 @@ jobs:
         node-version: ${{ matrix.node-version }}
     - name: Get yarn cache directory path
       id: yarn-cache-dir-path
-      run: echo "::set-output name=dir::$(yarn cache dir)"
+      run: echo "dir=$(yarn cache dir)" >> $GITHUB_OUTPUT
+      shell: bash
     - uses: actions/cache@v2
       id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
       with: