Dockerfile enhancement: multistage build

[vidixha]

This issue aims to refactor the current Dockerfile to use a multistage build approach. The motivation for this change is to:

1. Reduce final image size by excluding unnecessary build-time dependencies (e.g., gcc, libpython3-dev, etc.)
2. Enhance maintainability by clearly separating build and runtime concerns

Size of the current docker image: 3.82GB
Size of the docker image after multi-stage build: 1.06GB

Closes #990

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[vidixha]

Hi @DonggeLiu, could you please review this when you get a chance?
Thanks in advance!

[DonggeLiu]

Thanks @AkshataABhat
I will merge this into #995 to run experiments before merging this into main.