fix: replace --cov-omit CLI flag with pyproject.toml coverage config

pytest-cov 7.x dropped --cov-omit as a CLI argument; coverage omit
patterns now live in [tool.coverage.run] in pyproject.toml.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: DevOpsDerek

.github/workflows/ci.yml

@@ -77,8 +77,7 @@ jobs:
             --tb=short \
             --cov=. \
             --cov-report=term-missing \
-            --cov-report=xml \
-            --cov-omit="tests/*,exercises/*/exercise.py,lint.py"
+            --cov-report=xml
 
       - name: Upload coverage report
         # Only upload from one matrix entry to avoid duplicates

pyproject.toml

@@ -53,3 +53,10 @@ testpaths = ["tests"]
 addopts   = "-v --tb=short"
 # Exercise starter files contain intentional incomplete code — don't collect them
 norecursedirs = ["exercises"]
+
+[tool.coverage.run]
+source = ["."]
+omit   = ["tests/*", "exercises/*/exercise.py", "lint.py"]
+
+[tool.coverage.report]
+show_missing = true