infra: Add pull request presubmit checks, continuous `main` checks #12

	# Presubmit checks for PRs
	name: "presubmit"

	on:
	# Trigger on pull request rather than push, so that we can control whether
	# checks are run on a given PR (allowing checks to run automatically on PR
	# updates from third parties can be a security issue).
	pull_request:

	concurrency:
	group: ${{ github.workflow }}.${{ github.ref }}
	cancel-in-progress: true

	jobs:
	bazel-builder:
	# TODO(scott): Move to CI runners
	runs-on: ubuntu-latest
	timeout-minutes: 5

	steps:
	- uses: actions/checkout@v4
	- name: run all tests
	run: \|
	bazel test --config=presubmit //...

	golang-builder:
	runs-on: ubuntu-latest
	timeout-minutes: 5

	steps:
	- name: checkout
	uses: actions/checkout@v4
	- name: build all
	run: \|
	go build ./...
	- name: run all tests
	run: \|
	go test ./...

Provide feedback