Fix coverage: scope --cov to src/optimagic instead of ./

--cov=./ measured coverage of the entire repo including .tools/ and other
non-source files. Scoping to src/optimagic gives accurate results and
restores the codecov/project check. Also reverts the codecov target change
since the root cause is now fixed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: timmens

codecov.yml

@@ -12,8 +12,7 @@ coverage:
         target: 80%
     project:
       default:
-        target: auto
-        threshold: 1%
+        target: 90%
 ignore:
   # Uses numba
   - src/optimagic/benchmarking/cartis_roberts.py

pyproject.toml

@@ -451,7 +451,7 @@ pytest-xdist = ">=3.2"
 [tool.pixi.feature.test.tasks]
 tests = { cmd = "pytest", description = "Run the full test suite" }
 tests-fast = { cmd = "pytest -m 'not slow and not jax'", description = "Run tests excluding slow and jax tests" }
-tests-with-cov = { cmd = "pytest --cov-report=xml --cov=./", description = "Run tests with XML coverage report" }
+tests-with-cov = { cmd = "pytest --cov-report=xml --cov=src/optimagic", description = "Run tests with XML coverage report" }
 
 # --- Feature: typecheck (mypy + type stubs) ------------------------------------------
 [tool.pixi.feature.typecheck.dependencies]