Add conformance test cases for handling empty (zero byte) messages #2333

	name: ci
	on:
	push:
	branches: [main]
	pull_request:
	branches: [main]
	workflow_dispatch: {} # support manual runs
	permissions:
	contents: read
	jobs:
	ci:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	# When changing this, don't forget to also update
	# the version of Go used in the release.yaml workflow.
	go-version: [1.21.x, 1.22.x]
	steps:
	- name: Checkout Code
	uses: actions/checkout@v4
	with:
	fetch-depth: 1
	- name: Install Go
	uses: actions/setup-go@v5
	with:
	go-version: ${{ matrix.go-version }}
	- name: Cache
	uses: actions/cache@v4
	with:
	path: ~/go/pkg/mod
	key: ${{ runner.os }}-conformance-ci-${{ hashFiles('**/go.sum') }}
	restore-keys: ${{ runner.os }}-conformance-ci-
	- name: Install npm dependencies
	run: \|
	cd testing/grpcwebclient
	npm ci
	- name: Test
	run: make test
	- name: Run Conformance Tests
	run: make runconformance
	- name: Lint
	# Often, lint & gofmt guidelines depend on the Go version. To prevent
	# conflicting guidance, run only on the most recent supported version.
	# For the same reason, only check generated code on the most recent
	# supported version.
	if: matrix.go-version == '1.22.x'
	run: make checkgenerate && make lint
	- name: Check Release
	# We'll only be building releases w/ latest Go, so we only need to
	# test that it can be built w/ latest.
	if: matrix.go-version == '1.22.x'
	run: make checkrelease

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