chore(pyproject): Refine project configuration

Remove `icecream` from the `dev` dependency group to reduce default development dependencies. This allows users to explicitly add `icecream` if it is required for their specific development workflow.

Adjust `pytest` configuration by:
- Removing `--strict-config` and `--strict-markers` to provide more flexibility and avoid potential conflicts with certain test setups.
- Adding `consider_namespace_packages = true` to ensure pytest correctly discovers and runs tests within namespace packages.

Author: liblaf

template/pyproject.toml.jinja

@@ -38,7 +38,7 @@ dynamic = ["version"]
 "Source Code" = "https://github.com/{{ github_user }}/{{ github_repo }}"
 
 [dependency-groups]
-dev = ["icecream>=2,<3"]
+dev = []
 build = ["check-wheel-contents>=0.6,<0.7", "hatch>=1,<2", "twine>=6,<7"]
 docs = ["liblaf-mkdocs-preset>=0.2,<0.3", "mkdocs>=1,<2"]
 test = ["liblaf-pytest-preset>=0.1,<0.2", "pytest>=9,<10"]
@@ -92,10 +92,9 @@ addopts = [
   "--doctest-modules",
   "--hypothesis-show-statistics",
   "--import-mode=importlib",
-  "--showlocals",
-  "--strict-config",
-  "--strict-markers"
+  "--showlocals"
 ]
+consider_namespace_packages = true
 strict = true
 testpaths = ["benches", "src", "tests"]