ci: add minimum GitHub token permissions for workflows

[ashishkurmi]

Description

This PR adds minimum token permissions for the GITHUB_TOKEN in GitHub Actions workflows using https://github.com/step-security/secure-workflows.

The GitHub Actions workflow has a GITHUB_TOKEN with write access to multiple scopes.
Here is an example of the permissions in one of the workflow runs:
https://github.com/psf/requests/runs/8179910695?check_suite_focus=true#step:1:19

After this change, the scopes will be reduced to the minimum needed for the following workflows:

• codeql-analysis.yml
• lint.yml
• run-tests.yml

The following workflow already has the least privileged token permission set:

• lock-issues.yml

Motivation and Context

• This is a security best practice, so if the GITHUB_TOKEN is compromised due to a vulnerability or compromised Action, the damage will be reduced.
• GitHub recommends defining minimum GITHUB_TOKEN permissions.
  https://docs.github.com/en/actions/security-guides/automatic-token-authentication#modifying-the-permissions-for-the-github_token
• The Open Source Security Foundation (OpenSSF) Scorecards also treats not setting token permissions as a high-risk issue. This change will help increase the Scorecard score for this repository.

Signed-off-by: Ashish Kurmi akurmi@stepsecurity.io

[ashishkurmi]

@nateprewitt / @theGOTOguy / @sigmavirus24 : could you please review this PR?

[nateprewitt]

I believe we already have the whole repository set to read only but this seems reasonable. Thanks @boahc077.