Add label-based Slack channel routing - #7

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: aws-actions/amazon-ecr-login@4625ce35226a7557230889aae2f52eb50ec3dcda, aws-actions/configure-aws-credentials@00943011d9042930efac3dcd3a170e4273319bc8, docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4, docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2, docker/setup-qemu-action@29109295f81e9208d7d86ff1c6c12d2833863392. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/