Move @robdimsdale to emiritus roles

[robdimsdale]

I am no longer active in the paketo community, and I don't see that changing in the forseeable future.

So, I would like to be moved to emeritus role for all maintainer/contributor teams that I am a part of.

😞

cc @paketo-buildpacks/steering-committee

[jericop]

Sorry that is the case, but a huge thank you for all of contributions and stewardship!