Clean up unused vertex collections in JetBTaggingAlg
While investigating the impact of ACTS on FTAG secondary vertexing, I noticed that the secondary vertex collections were retrieved in the JetBTaggingAlg but not used. They are instead used in the BTagLightSecVertexing tool. They are consequently removed from the JetBTaggingAlg. Run 3 derivation outputs have been checked to be unchanged.