Update the direct scipy dependency to ~=1.2.1.

This means that we would accept a hot fix, but not accept major or minor version changes without releasing TFP.

PiperOrigin-RevId: 427916084

requirements.txt

@@ -5,7 +5,7 @@ matplotlib~=3.3.4
 mpmath
 numpy~=1.21.5
 pandas~=1.1.4
-scipy>=0.17
+scipy~=1.2.1
 tensorflow-datasets>=4.4.0
 tensorflow-estimator>=2.3.0
 tensorflow-probability>=0.13.0

setup.py

@@ -33,7 +33,7 @@ setup(
         'matplotlib~=3.3.4',
         'numpy~=1.21.5',
         'pandas~=1.1.4',
-        'scipy>=0.17',
+        'scipy~=1.2.1',
         'tensorflow-datasets>=4.4.0',
         'tensorflow-estimator>=2.3.0',
         'tensorflow-probability>=0.13.0',