ci: ignore sourceware.org for markdown link checks

[MikeMcC399]

Description

In markdown_link_check_config.json

• Add the following to ignorePatterns:
  • https://sourceware.org

Motivation and Context

The workflow .github/workflows/markdown-link-check.yml is sporadically failing with Status 0 errors:

  [✖] https://sourceware.org/glibc/ → Status: 0

See workflow logs

The following manually executed command is succeeding, although it is very slow:

curl -I https://sourceware.org/glibc/

Types of changes

• Documentation
• Version change (Update, remove or add more Node.js versions)
• Variant change (Update, remove or add more variants, or versions of variants)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Other (none of the above)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING.md document.
• All new and existing tests passed.