🩹 [Patch]: Add new secrets that the 'CI' and 'workflow' can handle

[MariusStorhaug]

Description

This pull request includes updates to the environment variables used in the GitHub Actions workflows and corresponding documentation. The changes primarily involve renaming and adding new environment variables for different types of GitHub Apps and tokens.

Updates to environment variables:

• .github/workflows/CI.yml: Renamed and added new environment variables for Enterprise and Organization GitHub Apps, as well as fine-grained personal access tokens. [1] [2]
• .github/workflows/workflow.yml: Made similar updates to environment variables for GitHub Apps and tokens as in CI.yml. [1] [2]

Documentation updates:

• README.md: Updated the list of environment variables to reflect the new names and additions for GitHub Apps and tokens.

Test updates:

• tests/tests/PSModuleTest.Tests.ps1: Updated the test script to check for the availability of the new environment variables.

Type of change

• 📖 [Docs]
• 🪲 [Fix]
• 🩹 [Patch]
• ⚠️ [Security fix]
• 🚀 [Feature]
• 🌟 [Breaking change]

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas