build(deps): bump ruby from 3.4.8 to 4.0.3 in /internal/test

Bumps ruby from 3.4.8 to 4.0.3.

---
updated-dependencies:
- dependency-name: ruby
  dependency-version: 4.0.3
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

internal/test/Dockerfile

@@ -1,10 +1,10 @@
 FROM golang AS go-image
 FROM docker.io/pivotalcfreleng/kiln:v0.110.0-rc2 AS kiln
 
-FROM ruby:3.4.8 AS builder
+FROM ruby:4.0.3 AS builder
 RUN mkdir -p -m 0700 ~/.ssh && ssh-keyscan github.com >> ~/.ssh/known_hosts
 
-FROM ruby:3.4.8
+FROM ruby:4.0.3
 
 # Install Go
 COPY --from=go-image /usr/local/go/ /usr/local/go/