Update license_finder gem installed in builder images to latest version
We use license_finder to gather the license information of Go dependencies - gitlab-org/omnibus-gitlab!2718 (merged). It is installed in the builder images themselves, so it can be used in multiple software definitions without being bundled in the package.
We are using a pretty old version, 3.1.1 there while the latest is 5.9.2. We should try updating it, and see if it reduces the size of support/dependency_decisions.yml file.
In my testing at gitlab-org/gitlab-omnibus-builder!117 (closed), its performance actually degraded as it stopped detecting ~100 libraries.