chore: update docker/setup-buildx-action github action to v2

[mileszim]

Updates github action docker/setup-buildx-action from v1 to v2 which

• moves Node 12 to Node 16
• stops using the setOutput workaround

which gets rid of some of these annoying annotation warnings during the build pipeline:

Node.js 12 actions are deprecated. Please update the following actions to use Node.js 16: docker/setup-buildx-action@v1. For more information see: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/

&

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/