fix(deps): update Dockerfiles from alpine:3.19.1 to alpine:3.20.0

[github-actions[bot]]

It's time to update Relay's Docker image Alpine versions. Alpine updates should generally be consumed as soon as possible since they contain patches for CVEs.

	Current repo configuration	Desired repo configuration
Alpine Version	alpine:3.19.1	alpine:3.20.0

This PR's change was generated by running:

./scripts/update-alpine-version.sh 3.20.0

• [x] I have triggered CI on this PR (either close & reopen this PR in Github UI, or git commit -m "run ci" --allow-empty && git push)