TrigAnalysisTest: Add AthFile cache clearing step in trigRel21 tests

Add a step removing the athfile-cache.ascii.gz file in tests where the Trigger step runs in release 21.0. These files produced in 21.0 are incompatible with python3 r22 and loading them in the downstream job leads to a SyntaxError. Simply removing them should avoid the problem.

Fixes ATR-21489

This merge request affects 1 package:

• Trigger/TrigValidation/TrigAnalysisTest

Adding @okumura ,@jpanduro as watchers

added Trigger master review-pending-level-1 labels

CI Result SUCCESS (hash f04438fd)

	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 0
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 22162]

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

merged

mentioned in commit b879d9b7

added sweep:ignore label