deps: bump production dependencies (otel v1.46.0, natspubsub v0.8.5) and fix CI breakage - #695

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: gotesttools/gotestfmt-action@v2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/