Fix AttributeError due to deprecated np.int → int

Fixes
```
Traceback (most recent call last):
  File "/cvmfs/cms.cern.ch/el9_amd64_gcc12/cms/cmssw/CMSSW_14_1_0_pre4/bin/el9_amd64_gcc12/pileupCalc.py", line 189, in <module>
    fillPileupHistogram(lumiInfo, options.calcMode,
  File "/cvmfs/cms.cern.ch/el9_amd64_gcc12/cms/cmssw/CMSSW_14_1_0_pre4/bin/el9_amd64_gcc12/pileupCalc.py", line 87, in fillPileupHistogram
    obs = binning.find(AveNumInt)
  File "/cvmfs/cms.cern.ch/el9_amd64_gcc12/cms/cmssw/CMSSW_14_1_0_pre4/bin/el9_amd64_gcc12/pileupCalc.py", line 65, in find
    return np.floor((x-self.xMin)*self.num/(self.xMax-self.xMin)).astype(np.int)
  File "/cvmfs/cms.cern.ch/el9_amd64_gcc12/external/py3-numpy/1.24.3-ac08ea497df571aa0b37dc29bb7a2045/lib/python3.9/site-packages/numpy/__init__.py", line 305, in __getattr__
    raise AttributeError(__former_attrs__[attr])
AttributeError: module 'numpy' has no attribute 'int'.
`np.int` was a deprecated alias for the builtin `int`. To avoid this error in existing code, use `int` by itself. Doing this will not modify any behavior and is safe. When replacing `np.int`, you may wish to use e.g. `np.int64` or `np.int32` to specify the precision. If you wish to review your current use, check the release note link for additional information.
The aliases was originally deprecated in NumPy 1.20; for more details and guidance see the original release note at:
    https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations
```

Author: IzaakWN

RecoLuminosity/LumiDB/scripts/pileupCalc.py

@@ -62,7 +62,7 @@ def __init__(self, num, xMin, xMax):
     def width(self):
         return (self.xMax-self.xMin)/self.num
     def find(self, x):
-        return np.floor((x-self.xMin)*self.num/(self.xMax-self.xMin)).astype(np.int)
+        return np.floor((x-self.xMin)*self.num/(self.xMax-self.xMin)).astype(int)
 
 Sqrt2 = np.sqrt(2)