chore(deps): update debian docker tag to v13 (#5)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Dockerfile

@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1
 
 # It's important that this is Debian 12 to match the distroless image.
-FROM debian:12-slim AS build
+FROM debian:13-slim AS build
 
 RUN --mount=type=cache,target=/var/lib/apt/lists \
     --mount=type=cache,target=/var/cache/apt \