TrigmuComb: Migrate from magnetic field service to CondAlg (ATR-21737)

As requested in ATR-21737, TrigmuComb code needs to be to be migrated from the AtlasFieldSvc to the new conditions algorithm. Code updated according to instructions in ATLASRECTS-5439.

added Trigger master labels

This merge request affects 1 package:

• Trigger/TrigAlgorithms/TrigmuComb

added review-pending-level-1 label

Relevant to all (Adding 2 more wrt to description, initial JIRA and double loading of mag field in SPOT):

https://its.cern.ch/jira/browse/ATLASRECTS-4687

https://its.cern.ch/jira/browse/ATLASRECTS-5432

https://its.cern.ch/jira/browse/ATLASRECTS-5439

https://its.cern.ch/jira/browse/ATR-21310

CI Result SUCCESS (hash 8fa11636)

	Athena	AthSimulation	AnalysisBase	AthGeneration
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
AnalysisBase: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 17350]

One minor comment (since anyhow this seems to be partially legacy code) is

//#include "MagFieldInterfaces/IMagFieldSvc.h"

why just comment and not remove ? It could help when we grep or search in lxr for clients for example if this was removed ...

Anyhow other than that looks good, following pretty much the instruction in the JIRAs, and since this is in parts legacy code and we want to get rid of this service quite soon , I leave it above to your judgement to do it or not here .

added review-approved label

removed review-pending-level-1 label

mentioned in merge request !34870 (merged)

merged

mentioned in commit 291a5dbb

added sweep:ignore label

mentioned in commit smh/athena@f1160686

mentioned in commit de3a8eda

mentioned in commit stsuno/athena@9534e0fe