Fix #456, Remove Linux sysmon implmentation from test file

[thnkslprpt]

Checklist

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License Agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution

• Fixes linux_sysmon.c implementation pasted into the test file #456
  • remove mistakenly copy-pasted file

Testing performed
GitHub CI actions all passing successfully (incl. Build + Run, Unit/Functional Tests etc.).

Expected behavior changes
None.

System(s) tested on
Debian 12 using the current main branch of cFS bundle.

Contributor Info
Avi Weiss   @thnkslprpt

[jphickey]

This one is weird. This was never really implemented in the first place. Apparently I was also the committer, which means it was probably incorrectly caught in a PR when it was not done.

While I agree it is totally wrong that the code is cut and pasted in there, this needs an update such that it actually implements tests for linux_sysmon.