Do pass posargs to tox invocation (#3587)

Co-authored-by: Dimitri Papadopoulos Orfanos <3234522+DimitriPapadopoulos@users.noreply.github.com>

tox.ini

diff --git a/tox.ini b/tox.ini
index dcde590..b93be53 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@
 [testenv:unitest]
 description = run unit tests
 dependency_groups = dev
-commands = pytest --cov=codespell_lib codespell_lib
+commands = pytest --cov=codespell_lib {posargs} codespell_lib
 
 [testenv:type]
 description = run type checks