PROD-2245 Use pip-compile to freeze requirements

[andres-torres-marroquin]

Closes #2245

Description Of Changes

Use pip-compile to freeze requirements.

Code Changes

• [ ] Renamed each of requirements files to *.in files: requirements.txt, dev-requirements.txt and optional-requirments.txt.
• [ ] Now when updating requirements, the *.in files are the ones to be updated, and after that a new nox command has to be ran: nox -s upgrade_packages.

Steps to Confirm

• [ ] Add a requirement to any of the *.in files.
• [ ] Run nox -s upgrade_packages.
• [ ] Verify corresponding requirement.txt file with new requirements.

Pre-Merge Checklist

• [ ] All CI Pipelines Succeeded
• Documentation:
  • [ ] documentation complete, PR opened in fidesdocs
  • [ ] documentation issue created in fidesdocs
  • [ ] if there are any new client scopes created as part of the pull request, remember to update public-facing documentation that references our scope registry
• [ ] Issue Requirements are Met
• [ ] Relevant Follow-Up Issues Created
• [ ] Update CHANGELOG.md
• [ ] For API changes, the Postman collection has been updated
• If there are any database migrations:
  • [ ] Ensure that your downrev is up to date with the latest revision on main
  • [ ] Ensure that your downgrade() migration is correct and works
    • [ ] If a downgrade migration is not possible for this change, please call this out in the PR description!