Installation script: Support checksum signature verification

[hibare]

What would you like to be added:

Grype simplifies the installation process through a convenient script. The current script includes a checksum validation step for the binary being installed. Since Grype utilizes cosign to sign the checksum file, it would be beneficial to enhance the installation script by incorporating checksum signature validation.

Why is this needed:

This enhancement ensures consumers can effortlessly verify the installation of binaries, eliminating the need for manual verification.

Additional context:

[tgerla]

Hi @hibare, thank you for the suggestion! I think we would be open to this feature in the install script, especially if it were triggered by a command line flag. We are hesitant to make our installation script rely on a 3rd party program (cosign), but if it were an optional parameter I think that would be fine. Is this something you'd be interested in working on? We'd be happy to help.

[hibare]

Hello @tgerla Yes, it'll be an optional parameter to the installation script. I'll be submitting a pull request in the coming days.