Remove unused headers

[jennuine]

🦟 Bug fix

Summary

Remove unused headers, which were causing the abi checker to fail (first detected in #486)

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
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[methylDragon]

This PR needs #486 to pass
I say we just force a merge 😬, since we'll need a forced merge anyway to get the ABI checker to be happy.

Help! @scpeters ?

[scpeters]

@osrf-jenkins run tests please

[jennuine]

@scpeters #486 fixes INTEGRATION_ExamplesBuild_TEST but the abi checker is failing. This PR should fix abi but (from my understanding) not until after it's merged. I do not have privileges to override the merge