Switch to system version of octomap.

[clalancette]

Description

This is so that we have a consistent ABI between these packages and anything else in the system that depends on octomap. We'll eventually be removing the ROS-provided version of octomap to make sure we don't have these problems in the future.

This should solve the issue in https://github.com/ros/rosdistro/issues/41622 , and was enabled by the merging of https://github.com/ros/rosdistro/pull/41623

Checklist

• [N/A] Required by CI: Code is auto formatted using clang-format
• [N/A] Extend the tutorials / documentation reference
• [N/A] Document API changes relevant to the user in the MIGRATION.md notes
• [N/A] Create tests, which fail without this PR reference
• [N/A] Include a screenshot if changing a GUI
• [ ] While waiting for someone to review your request, please help review another open pull request to support the maintainers