Update dependencies and fix coverage to reach 100%

This commit updates all dependencies to their latest compatible versions
and resolves issue #1 by excluding the pymodule line from coverage.

Changes:
- Update GitHub Actions workflow:
  * Replace deprecated actions-rs/toolchain with dtolnay/rust-toolchain
  * Update actions/checkout from v4 to v5
- Update Python dependencies:
  * pytest: 8.3.4 → 8.4.2
  * maturin: 1.8.1 → 1.9.6
  * Update build-system to require maturin>=1.9
- Update Rust dependencies:
  * PyO3: 0.23.3 → 0.23.5 (latest patch release, no breaking changes)
- Fix coverage to reach 100%:
  * Add #[cfg_attr(coverage, coverage(off))] to _foobar pymodule
  * This excludes the pymodule initialization code that cannot be
    directly tested (see rust-lang/rust#84605)

All updates are backwards-compatible and maintain test compatibility.
The coverage fix resolves issue #1 without affecting functionality.

Fixes #1

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: claude

.github/workflows/CI.yml

@@ -12,19 +12,16 @@ jobs:
         os: ["ubuntu"]
     runs-on: ${{ matrix.os }}-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"
       - name: Install uv
         uses: astral-sh/setup-uv@v5
         with:
           enable-cache: true
-      - uses: actions-rs/toolchain@v1
+      - uses: dtolnay/rust-toolchain@stable
         with:
-          toolchain: stable
-          override: true
-          profile: minimal
           components: llvm-tools-preview
       - name: Install cargo-llvm-cov
         uses: taiki-e/install-action@cargo-llvm-cov

Cargo.toml

@@ -9,7 +9,7 @@ name = "foobar"
 crate-type = ["cdylib"]
 
 [dependencies]
-pyo3 = { version = "0.23.3", features = ["extension-module"] }
+pyo3 = { version = "0.23.5", features = ["extension-module"] }
 
 [package.metadata.maturin]
 python-source = "python"

pyproject.toml

@@ -8,13 +8,13 @@ classifiers = [
     "Programming Language :: Python :: Implementation :: PyPy",
 ]
 dependencies = [
-    "pytest>=8.3.4",
+    "pytest>=8.4.2",
     "pytest-cov>=6.0.0",
-    "maturin>=1.8.1",
+    "maturin>=1.9.6",
 ]
 
 [build-system]
-requires = ["maturin>=1.0,<2.0"]
+requires = ["maturin>=1.9,<2.0"]
 build-backend = "maturin"
 
 [tool.maturin]

src/lib.rs

@@ -13,6 +13,7 @@ fn pyo3_sum(a: usize, b: usize) -> PyResult<usize> {
 }
 
 /// A Python module implemented in Rust.
+#[cfg_attr(coverage, coverage(off))]
 #[pymodule]
 fn _foobar(_py: Python, m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(pyo3_sum, m)?)?;