Upgrade cache action to avoid deprecation

The warnings are:

* `Node.js 12 actions are deprecated. For more information see: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/. Please update the following actions to use Node.js 16: actions/checkout, actions/cache, actions/upload-artifact, actions/cache, actions/checkout`
* `The `save-state` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/`
* `The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/`

.github/workflows/build.yml

@@ -12,7 +12,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
       - name: Cache west modules
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         env:
           cache-name: cache-zephyr-modules
         with: