feat: rm JChainMultifactory (#1421)

### Briefly, what does this PR introduce?
This PR removes the JChainMultifactory, now that no factory is using it
anymore.

TODO:
- [x] #1418 
- [x] #1419 

### What kind of change does this PR introduce?
- [ ] Bug fix (issue #__)
- [x] New feature (issue #__)
- [ ] Documentation update
- [ ] Other: __

### Please check if this PR fulfills the following:
- [ ] Tests for the changes have been added
- [ ] Documentation has been added / updated
- [ ] Changes have been communicated to collaborators

### Does this PR introduce breaking changes? What changes might users
need to make to their code?
No.

### Does this PR change default behavior?
No.

src/detectors/DRICH/DRICH.cc

@@ -17,7 +17,6 @@
 #include "algorithms/pid/IrtCherenkovParticleIDConfig.h"
 #include "algorithms/pid/MergeParticleIDConfig.h"
 #include "algorithms/tracking/TrackPropagationConfig.h"
-#include "extensions/jana/JChainMultifactoryGeneratorT.h"
 #include "extensions/jana/JOmniFactoryGeneratorT.h"
 // factories
 #include "global/digi/PhotoMultiplierHitDigi_factory.h"

src/factories/fardetectors/FarDetectorLinearTracking_factory.h

@@ -8,8 +8,7 @@
 #include <edm4eic/TrackSegment.h>
 #include <algorithms/fardetectors/FarDetectorLinearTracking.h>
 
-#include <extensions/jana/JChainMultifactoryT.h>
-#include <extensions/spdlog/SpdlogMixin.h>
+#include <extensions/jana/JOmniFactory.h>
 #include <spdlog/logger.h>
 
 namespace eicrecon {