build: Update lower bounds to jsonschema v4.15.0, importlib-resources v1.4.0 (#1979)

* Update lower bound of the supported jsonschema versions to v4.15.0 to use the
  required improvements to jsonschema.RefResolver used in PR #1976.
   - c.f. https://github.com/orgs/python-jsonschema/discussions/995
   - Amends PR #1976.
* Update lower bound of the supported importlib-resources versions to v1.4.0 as
  > jsonschema 4.15.0 depends on importlib-resources>=1.4.0; python_version < "3.9"
* Update tests/constraints.txt to use jsonschema==4.15.0 and importlib_resources==1.4.0.

Author: matthewfeickert

setup.cfg

@@ -38,10 +38,10 @@ install_requires =
     scipy>=1.1.0 # requires numpy, which is required by pyhf and tensorflow
     click>=8.0.0  # for console scripts
     tqdm>=4.56.0  # for readxml
-    jsonschema>=3.0.0  # for utils
+    jsonschema>=4.15.0  # for utils
     jsonpatch>=1.15
     pyyaml>=5.1  # for parsing CLI equal-delimited options
-    importlib_resources>=1.3.0; python_version < "3.9"  # for resources in schema
+    importlib_resources>=1.4.0; python_version < "3.9"  # for resources in schema
     typing_extensions>=3.7.4.3; python_version == "3.7"  # for SupportsIndex
 
 [options.packages.find]

tests/constraints.txt

@@ -2,10 +2,10 @@
 scipy==1.1.0
 click==8.0.0  # c.f. PR #1958, #1909
 tqdm==4.56.0
-jsonschema==3.0.0
+jsonschema==4.15.0  # c.f. PR #1979
 jsonpatch==1.15
 pyyaml==5.1
-importlib_resources==1.3.0
+importlib_resources==1.4.0  # c.f. PR #1979
 typing-extensions==3.7.4.3  # c.f. PR #1961, #1940
 # xmlio
 uproot==4.1.1