Fix numpy 1.25 deprecation warnings (#372)

* fix deprecation warnings

* adding disallow_deprecations to tests

* address comments

.github/test_real.sh

@@ -11,4 +11,4 @@ cd tests
 # we have to copy over the coveragerc file to make sure it's in the
 # same directory where codecov is run
 cp ../.coveragerc .
-testflo --pre_announce -v --coverage --coverpkg pyoptsparse $EXTRA_FLAGS
+testflo --pre_announce --disallow_deprecations -v --coverage --coverpkg pyoptsparse $EXTRA_FLAGS

pyoptsparse/pyOpt_solution.py

@@ -1,6 +1,9 @@
 # Standard Python modules
 import copy
 
+# External modules
+import numpy as np
+
 # Local modules
 from .pyOpt_optimization import Optimization
 
@@ -49,9 +52,9 @@ def __init__(self, optProb, xStar, fStar, lambdaStar, optInform, info):
                 i += 1
 
         # Now set the f-values
-        if isinstance(fStar, float) or len(fStar) == 1:
-            self.objectives[list(self.objectives.keys())[0]].value = float(fStar)
-            fStar = float(fStar)
+        if isinstance(fStar, np.ndarray) and len(fStar) == 1:
+            self.objectives[list(self.objectives.keys())[0]].value = fStar.item()
+            fStar = fStar.item()
         else:
             for f_name, f in self.objectives.items():
                 f.value = fStar[f_name]