Make upgrade and update minimum Go version to 1.21 #917

	name: Buf CI
	on:
	push:
	pull_request:
	types: [opened, synchronize, reopened, labeled, unlabeled]
	delete:
	permissions:
	contents: read
	pull-requests: write
	jobs:
	buf:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- uses: bufbuild/buf-action@v1
	with:
	token: ${{ secrets.BUF_TOKEN }}

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