AthenaAuditors + PerfMonGPerfTools: No longer turn off the build of AthenaAuditors and PerfMonGPerfTools in the absence of GPerfTools

As discussed in ATEAM-654, with this MR we no longer turn off the AthenaAuditors and PerfMonGPerfTools build in the absence of gperftools. The original workaround was needed because the clang8 build of LCG_96 didn't provide gperftools, which is not relevant any longer. Also, it overshadows problems w/ gperftools in general.

cc: @fwinkl @akraszna

This merge request affects 2 packages:

• Control/AthenaAuditors
• Control/PerformanceMonitoring/PerfMonGPerfTools

Adding @amete ,@ssnyder as watchers

added Core master review-pending-level-1 labels

CI Result SUCCESS (hash df8fb101)

	Athena	AthSimulation	AthGeneration	AnalysisBase
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 5
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 20477]

Compilation warnings don't look related.

-s

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit fed236f6

added sweep:ignore label