Maintenance: Update CI Workflows

[RHammond2]

Update CI workflows for latest versions

This PR updates the GitHub Actions workflows to remove now unnecessary runners (GH Pages and CI Docs) and updates the remaining runners to ensure their actions versions are the latest with updates to Python versioning where applicable. Some other updates have been made to fully utilize existing runners and remove functionality that is out of date.

Section 1: Type of Contribution

• Feature Enhancement
  • Framework
  • New Model
  • Updated Model
  • Tools/Utilities
  • Other (please describe):
• Bug Fix
• Documentation Update
• CI Changes
• Other (please describe):

Section 2: Draft PR Checklist

• Open draft PR
• Describe the feature that will be added
• Fill out TODO list steps
• Describe requested feedback from reviewers on draft PR
• Complete Section 7: New Model Checklist (if applicable)

TODO:

• Step 1
• Step 2

Type of Reviewer Feedback Requested (on Draft PR)

Structural feedback:

Implementation feedback:

Other feedback:

Section 3: General PR Checklist

• PR description thoroughly describes the new feature, bug fix, etc.
• Added tests for new functionality or bug fixes
• Tests pass (If not, and this is expected, please elaborate in the Section 6: Test Results)
• Documentation
  • Docstrings are up-to-date
  • Related docs/ files are up-to-date, or added when necessary
  • Documentation has been rebuilt successfully
  • Examples have been updated (if applicable)
• CHANGELOG.md has been updated to describe the changes made in this PR

Section 3: Related Issues

N/A

Section 4: Impacted Areas of the Software

Section 4.1: New Files (N/A)

• path/to/file.extension
  • method1: What and why something was changed in one sentence or less.

Section 4.2: Modified Files

• .github/workflows/ci_docs.yml: Removed because of the addition of a RTD-based docs builder on PRs.
• .github/workflows/gh_pages.yml: Removed since RTD is preferenced for the docs.
• .github/workflows/pre-commit.yml: Adds the runner to all PRs on develop and main to ensure consistent code in the primary working branches. Updates the actions and Python versions.
• .github/workflows/ci.yml: Removes flake8 in favor of the pre-commit workflow. Updates the actions and Python versions.
• .github/workflows/publish_to_pypi.yml: Updates the actions and Python versions.
• .github/workflows/publish_to_test_pypi.yml: Updates the actions and Python versions.

Section 5: Additional Supporting Information

This is partially prompted by the addition of a Read The Docs build step that was recently added, otherwise these are items I noticed while checking in on the current workflows.

Section 6: Test Results, if applicable

N/A

Section 7 (Optional): New Model Checklist

• Model Structure:
  • Follows established naming conventions outlined in docs/developer_guide/coding_guidelines.md
  • Used attrs class to define the Config to load in attributes for the model
    • If applicable: inherit from BaseConfig or CostModelBaseConfig
  • Added: initialize() method, setup() method, compute() method
    • If applicable: inherit from CostModelBaseClass
• Integration: Model has been properly integrated into H2Integrate
  • Added to supported_models.py
  • If a new commodity_type is added, update create_financial_model in h2integrate_model.py
• Tests: Unit tests have been added for the new model
  • Pytest-style unit tests
  • Unit tests are in a "test" folder within the folder a new model was added to
  • If applicable add integration tests
• Example: If applicable, a working example demonstrating the new model has been created
  • Input file comments
  • Run file comments
  • Example has been tested and runs successfully in test_all_examples.py
• Documentation:
  • Write docstrings using the Google style
  • Model added to the main models list in docs/user_guide/model_overview.md
    • Model documentation page added to the appropriate docs/ section
    • <model_name>.md is added to the _toc.yml