Fixes flaky RobotState test (backport #3105)

[mergify]

Description

Fixes #3103 by ensuring that the dirty_link_transforms_ member is cleared before querying the RobotState

See #3102 for more details on the cause.

TLDR:

Setting the build type to Release causes tests to silently fail, whereas Debug does not (some tests rely on assert calls, which are enabled / disabled based on the presence of the NDBUG macro variable, which is set by CMake depending on the build type).

See the SonarScan pipeline call to ros-industrial/industrial_ci@master, which sets DCMAKE_BUILD_TYPE to Debug (and where the tests fail), and the same call in the rolling-ci pipeline (where the tests pass), which sets the same variable to Release.

I've also added a comment (and demonstration of the fix, at least for this test) locally.

Checklist

• Required by CI: Code is auto formatted using clang-format
• Extend the tutorials / documentation reference
• Document API changes relevant to the user in the MIGRATION.md notes
• Create tests, which fail without this PR reference
• 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

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This is an automatic backport of pull request #3105 done by [Mergify](https://mergify.com).