[fix]: remove db-migration step from infisical.yaml

[zaaakher]

The db-migration step in the docker compose caused issues that I shared in this discord post
Basically last week Infisical made a release that does the db-migration automatically. Read more and including it in the docker compose caused issues that prevented infisicial from working altogether. So this PR fixes it.

Changes

• Remove the db-migration part from the infisical.yaml template

[zaaakher]

Update

I added SMTP environment variables to the docker compose since Infisical expects them as per their email configuration docs https://infisical.com/docs/self-hosting/configuration/envars#resend

[zaaakher]

On a side note, I found out (the hard way) that I have to map the port 8080 to the custom domain I added to the infisical backend service.
https://example.com didn't work and I had to do https://example.com:8080

Is there a way the port mapping could be configured automatically when using Infisical template? So that future users can just set their custom domain without having to worry about the port.