Ensure there is one space between the number and GB, MB, etc.

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What does this MR do and why?

This MR adds a space between a number and GB, MB, etc. It excludes changes defined by a code, but includes the changes to comments within the code block.

Affected pages:

1. administration/backup_restore/backup_gitlab.md
2. administration/gitlab_duo_self_hosted/supported_models_and_hardware_requirements.md
3. administration/operations/puma.md
4. administration/raketasks/maintenance.md
5. development/migration_style_guide.md
6. development/packages/new_format_development.md
7. install/requirements.md
8. topics/runner_fleet_design_guides/gitlab_runner_fleet_config_and_best_practices.md
9. user/clusters/agent/vulnerabilities.md
10. user/packages/package_registry/tutorial_generate_sbom.md
11. user/project/settings/import_export_troubleshooting.md

References

#330052 (closed)

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