Add an option to use at build step

[benoitlahoz]

Description

This PR adds an apply option to the plugin that takes serve (the original) or build, so it can be used when building with vite.

mkcert({
  apply: 'build'
});

Additional context

The use case is for testing production environment locally when not using vite serve.

yarn build # Bundle server with vite

yarn start # NODE_ENV=production node ./dist/server/main.js

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other