GSFSmoother: remove a few dynamic_cast

This merge request affects 1 package:

• Tracking/TrkFitter/TrkGaussianSumFilter

Adding @amorley as watcher

added Egamma Tracking master review-pending-level-1 labels

CI Result SUCCESS (hash 4ad242ef)

	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 17794]

mentioned in commit ac6c952e

merged

added sweep:ignore label