Updates steps to remove projects references

[desertaxle]

This PR removes references to projects in this library.

Renames:

• prefect_gcp.projects -> prefect_gcp.deployments
• pull_project_from_gcs -> pull_from_gcs
• push_project_to_gcs -> push_to_gcs
• PullProjectFromGcsOutput -> PullFromGcsOutput
• PushProjectTGcsOutput -> PushToGcsOutput

Part of PrefectHQ/prefect#9860

Screenshots

Checklist

• References any related issue by including "Closes #" or "Closes ".
  • If no issue exists and your change is not a small fix, please create an issue first.
• Includes tests or only affects documentation.
• Passes pre-commit checks.
  • Run pre-commit install && pre-commit run --all locally for formatting and linting.
• Includes screenshots of documentation updates.
  • Run mkdocs serve view documentation locally.
• Summarizes PR's changes in CHANGELOG.md