chore: bump sam/build-java21 (#2226)

Bumps sam/build-java21 from `e12c501` to `068d2ab`.

---
updated-dependencies:
- dependency-name: sam/build-java21
  dependency-version: '068d2ab1eee017c2557b7a3879a9f9cc79ba0d5d8b177af5949437eee96458cd'
  dependency-type: direct:production
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

powertools-e2e-tests/src/test/resources/docker/Dockerfile

@@ -1,5 +1,5 @@
 # Use the official AWS SAM base image for Java 21
-FROM public.ecr.aws/sam/build-java21@sha256:e12c501aa7d3d3dc04be0d900115a0339c73f523ad73a9aecd9e99499413c465
+FROM public.ecr.aws/sam/build-java21@sha256:068d2ab1eee017c2557b7a3879a9f9cc79ba0d5d8b177af5949437eee96458cd
 
 # Install GraalVM dependencies
 RUN curl -4 -L https://download.oracle.com/graalvm/21/latest/graalvm-jdk-21_linux-x64_bin.tar.gz | tar -xvz