ci: update GH token

[brionmario]

Purpose

This pull request updates the GitHub Actions workflows to use a new secret for authentication. The most important changes involve replacing the GH_TOKEN environment variable with a new token.

Updates to GitHub Actions workflows:

• .github/workflows/deploy-gh-pages.yml: Replaced GH_TOKEN with secrets.ASGARDEO_GITHUB_BOT_TOKEN for the GH_TOKEN environment variable.
• .github/workflows/release.yml: Replaced GH_TOKEN with secrets.ASGARDEO_GITHUB_BOT_TOKEN for the GH_TOKEN environment variable.

Related Issues

• N/A

Related PRs

• N/A

Checklist

• e2e cypress tests locally verified.
• Manual test round performed and verified.
• UX/UI review done on the final implementation.
• Documentation provided. (Add links if there are any)
• Unit tests provided. (Add links if there are any)
• Integration tests provided. (Add links if there are any)

Security checks

• Followed secure coding standards in http://wso2.com/technical-reports/wso2-secure-engineering-guidelines?
• Ran FindSecurityBugs plugin and verified report?
• Confirmed that this PR doesn't commit any keys, passwords, tokens, usernames, or other secrets?