rt-tests: Install rtla from mainline instead from Debian packages repository

[musamaanjum]

We use rtla package from Debian repository to run 2 tests (osnoise and timerlat). This tool is present in the mainline (tools/tracing/rtla). We should install the latest tool from mainline instead of installing from debian package. Because of the old package, these tests are partially run.

In the discussion thread, Daniel Wagner has mentioned that although the ABI of rtla is maintained. There could be newer features and enhacements in the mainline version of the rtla tool.

This is a lower-priority task and the only placeholder that we should update the installation of rtla tool.

cc: @helen-fornazier

[musamaanjum]

Related to: kernelci/kernelci-project#439