Bump golang in /examples/deployment/docker/log_server

Bumps golang from `cbee5d2` to `c4b696f`.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

examples/deployment/docker/log_server/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.21.6-bookworm@sha256:cbee5d27649be9e3a48d4d152838901c65d7f8e803f4cc46b53699dd215b555f as build
+FROM golang:1.21.6-bookworm@sha256:c4b696f1b2bf7d42e02b62b160c3f81c39386e1c567603df8c514ad6ce93361d as build
 
 WORKDIR /trillian