ENH: Consider warnings as errors when running pytest

Consider warnings as errors when running `pytest`: exclude the `min`
dependencies configuration as warnings are expected with older versions.

Author: jhlegarreta

.github/workflows/build_test_deploy.yml

@@ -31,6 +31,7 @@ env:
   # Force tox and pytest to use color
   FORCE_COLOR: true
   TEMPLATEFLOW_HOME: /tmp/templateflow
+  NIFREEZE_WERRORS: 1
 
 jobs:
   build:

tox.ini

@@ -67,7 +67,7 @@ uv_resolution =
   min: lowest-direct
 
 commands =
-  pytest --durations=20 --durations-min=1.0 --cov-report term-missing {posargs:-n auto}
+  pytest --durations=20 --durations-min=1.0 --cov-report term-missing !min: -Werror {posargs:-n auto}
 
 [testenv:style]
 description = Check our style guide