Add faster-cache extra, test in CI (python#17978)

Follow up to python#17955

setup.py

@@ -232,6 +232,7 @@ def run(self):
         "python2": "",
         "reports": "lxml",
         "install-types": "pip",
+        "faster-cache": "orjson",
     },
     python_requires=">=3.8",
     include_package_data=True,

tox.ini

@@ -20,15 +20,18 @@ passenv =
     PROGRAMDATA
     PROGRAMFILES(X86)
     PYTEST_ADDOPTS
-deps = -rtest-requirements.txt
+deps =
+    -r test-requirements.txt
+    # This is a bit of a hack, but ensures the faster-cache path is tested in CI
+    orjson;python_version=='3.12'
 commands = python -m pytest {posargs}
 
 [testenv:dev]
 description = generate a DEV environment, that has all project libraries
 usedevelop = True
 deps =
-    -rtest-requirements.txt
-    -rdocs/requirements-docs.txt
+    -r test-requirements.txt
+    -r docs/requirements-docs.txt
 commands =
     python -m pip list --format=columns
     python -c 'import sys; print(sys.executable)'
@@ -38,7 +41,7 @@ commands =
 description = invoke sphinx-build to build the HTML docs
 passenv =
     VERIFY_MYPY_ERROR_CODES
-deps = -rdocs/requirements-docs.txt
+deps = -r docs/requirements-docs.txt
 commands =
     sphinx-build -n -d "{toxworkdir}/docs_doctree" docs/source "{toxworkdir}/docs_out" --color -W -bhtml {posargs}
     python -c 'import pathlib; print("documentation available under file://\{0\}".format(pathlib.Path(r"{toxworkdir}") / "docs_out" / "index.html"))'