Move @pivotal-david-osullivan to Emeritus member

[dmikusa]

I would like to propose we move @pivotal-david-osullivan into an Emeritus Maintainer position for the Utilities subteam. After being a long time maintainer on the team, @pivotal-david-osullivan has moved onto other projects. Thank you for everything you've done for the project, @pivotal-david-osullivan!

@paketo-buildpacks/utilities-maintainers please vote as to whether we should officially make this change
cc @paketo-buildpacks/steering-committee