Refactor Dockerfile use less layer

[ningmingxiao]

assembler docker image is too big
before this commit 5.17GB after this commit 4.73GB

[openshift-ci]

Hi @ningmingxiao. Thanks for your PR.

I'm waiting for a github.com member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[gemini-code-assist]

Code Review

This pull request aims to reduce the number of layers in the Docker image by consolidating RUN commands, which is a great goal for optimizing image size and build speed.

The consolidation of the first set of RUN commands is done well. However, the second, larger RUN block introduces a critical issue where shell comments break the command chain, preventing most of the commands from executing. It also includes an unsafe directory removal operation.

My review includes a critical comment with a suggested fix that resolves these issues while preserving the single-layer approach and improving code style.