Bump debian in /.github/docker

Bumps debian from bookworm-20240812 to bookworm-20240904.

---
updated-dependencies:
- dependency-name: debian
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/docker/Dockerfile.debian

@@ -1,3 +1,3 @@
-FROM debian:bookworm-20240812
+FROM debian:bookworm-20240904
 
 CMD echo this is a dummy file used to automate dependency upgrades for plugins