Remove unused end-point

Both PlotApi and webviz-ert uses the /records/observations endpoint

src/ert/dark_storage/common.py

@@ -258,10 +258,6 @@ def _get_observations(
     return observations
 
 
-def get_all_observations(experiment: Experiment) -> list[dict[str, Any]]:
-    return _get_observations(experiment)
-
-
 def get_observations_for_obs_keys(
     ensemble: Ensemble, observation_keys: list[str]
 ) -> list[dict[str, Any]]:

src/ert/dark_storage/endpoints/__init__.py

@@ -3,14 +3,12 @@
 from .compute.misfits import router as misfits_router
 from .ensembles import router as ensembles_router
 from .experiments import router as experiments_router
-from .observations import router as observations_router
 from .records import router as records_router
 from .updates import router as updates_router
 
 router = APIRouter()
 router.include_router(experiments_router)
 router.include_router(ensembles_router)
 router.include_router(records_router)
-router.include_router(observations_router)
 router.include_router(updates_router)
 router.include_router(misfits_router)