It’s true that Google doesn’t host official public archives of old Chrome versions, including 109, since they focus on supporting only current, secure releases. Most reputable vendors actively discourage use of outdated browsers due to the security risks, especially on unsupported OS like Windows 7.
If you absolutely must run something like Chrome 109, be extra cautious: only obtain installers from sources you or your organization trust implicitly. Avoid unofficial “mirrors” as those often risk tampering.
For better security, consider alternatives still offering Win7 patches, like Mozilla Firefox ESR (which supports Windows 7 a bit longer), or run legacy apps in a virtual machine isolated from your primary work environment. Also, keep your system behind a strong firewall and avoid sensitive activities on unsupported platforms whenever possible.