Optimize CI/CD by running actions only when related files have been changed

[Vadorequest]

Is your feature request related to a problem? Please describe. Optimize the heavy deploy-vercel-staging/production.yml workflows by running them only when related files have been changed.

Describe the solution you'd like Ignore run when:

• A Story has been changed (affects Storybook, not the Next.js app)
• A change in .storybook is made
• Another workflow is changed
• .env, .gitignore files are changed
• vercel customer files are changed (except for the default customer)

Basically, ignoring those files (or, allowing other files only) would avoid deploying needlessly, which would result in faster deployments, reduced feedback of what really matters, and lowering costs (GHA, Vercel)

Additional context

We've done something similar for storybook, using paths, basically using a "whitelist" and ignoring other changes:

on:
  push: # Triggers on each pushed commit
    branches:
      - '*'
    # Only run the workflow when there are changes made to files, in any of the below paths
    # Optimize our CI/CD by not running Storybook needlessly (faster deploy, lower cost)
    paths:
      - '.github/workflows/deploy-vercel-storybook.yml'
      - '.storybook/**'
      - 'cypress/integration-storybook/**'
      - 'src/stories/**'
      - 'src/components/**'
      #      - 'src/*/components/**' # For later?
      - 'package.json'

[Vadorequest]

Done in https://github.com/UnlyEd/next-right-now/pull/282