build: Update lower bounds of scipy to v1.5.1 (#2081)

* Update lower bounds of scipy to v1.5.1 to ensure that the minimum supported dependencies
  workflow passes, as it failed nondeterministically for v1.5.0.
* Amends PR #2079.

Author: matthewfeickert

setup.cfg

@@ -34,7 +34,7 @@ package_dir =
 include_package_data = True
 python_requires = >=3.8
 install_requires =
-    scipy>=1.5.0 # requires numpy, which is required by pyhf and tensorflow
+    scipy>=1.5.1 # requires numpy, which is required by pyhf and tensorflow
     click>=8.0.0  # for console scripts
     tqdm>=4.56.0  # for readxml
     jsonschema>=4.15.0  # for utils

tests/constraints.txt

@@ -1,5 +1,5 @@
 # core
-scipy==1.5.0  # c.f. PR #2079
+scipy==1.5.1  # c.f. PR #2081
 click==8.0.0  # c.f. PR #1958, #1909
 tqdm==4.56.0
 jsonschema==4.15.0  # c.f. PR #1979