Build: Reference GitHub Actions by commit SHAs

The SHAs are verified to come from the original repositories and not forks.

For reference:

https://github.com/actions/checkout/releases/tag/v3.5.2
actions/checkout@8e5e7e5

https://github.com/actions/cache/releases/tag/v3.3.1
actions/cache@88522ab

https://github.com/actions/setup-node/releases/tag/v3.6.0
actions/setup-node@64ed1c7

Fixes gh-5266
Closes gh-5269

Signed-off-by: Gabriela Gutierrez <gabigutierrez@google.com>

(cherry picked from commit 784b9ba)

.github/workflows/node.js.yml

@@ -42,18 +42,18 @@ jobs:
             BROWSERS: "FirefoxHeadless"
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
 
     - name: Cache
-      uses: actions/cache@v3
+      uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8 # v3.3.1
       with:
         path: ~/.npm
         key: ${{ runner.os }}-node-${{ matrix.NODE_VERSION }}-npm-lock-${{ hashFiles('**/package-lock.json') }}
         restore-keys: |
           ${{ runner.os }}-node-${{ matrix.NODE_VERSION }}-npm-lock-
 
     - name: Use Node.js ${{ matrix.NODE_VERSION }}
-      uses: actions/setup-node@v3.6.0
+      uses: actions/setup-node@64ed1c7eab4cce3362f8c340dee64e5eaeef8f7c # v3.6.0
       with:
         node-version: ${{ matrix.NODE_VERSION }}