ISF_Fatras: Only create PhysicsValidationTool when ValidationMode is activated

I noticed that the PhysicsValidationTool was being created in every ATLFAST3F_G4MS job even if flags.Sim.ISF.Validation was set to False. This merge request ensures that the ToolHandle is disabled when not required. (Prevents some warnings and should save a small amount of memory.)

Also demoted some INFO messages to DEBUG.

This merge request affects 3 packages:

• Simulation/ISF/ISF_Fatras/ISF_FatrasServices
• Simulation/ISF/ISF_Fatras/ISF_FatrasTools
• Simulation/ISF/ISF_Fatras/ISF_FatrasToolsG4

Affected files list will not be printed in this case

Adding @lmijovic ,@jchapman ,@tcuhadar as watchers

added Egamma Simulation main review-pending-level-1 labels

added PhysValidation label

CI Result SUCCESS (hash 81b36474)

	Athena
externals
cmake
make
tests

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Athena: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-EL9 10395] (remote access info)

Looks good, approving - L2

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

merged

mentioned in commit 480b7b9a