Update compose.yml

[l4rm4nd]

Implement fix to fallback to linux if the env variable DEPLOY_PLATFORM was not set by the user.

This fixes the warning message when docker compose config is run on the provided docker-comose.yml file to validate its proper syntax.

The command will print the following warning message:

msg="The \"DEPLOY_PLATFORM\" variable is not set. Defaulting to a blank string."

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