Change CI toolchain to stable (#355)

.github/workflows/ci.yml

@@ -35,7 +35,7 @@ jobs:
       - name: Rust toolchain
         uses: dtolnay/rust-toolchain@7b1c307e0dcbda6122208f10795a713336a9b35a
         with:
-          toolchain: "1.73.0"
+          toolchain: "stable"
           components: rustfmt
 
       - name: Check Formatting
@@ -47,7 +47,7 @@ jobs:
       UNSAFE_PYO3_SKIP_VERSION_CHECK: ${{ matrix.unsafe-pyo3-skip-version-check }}
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-latest, windows-2019]
         python-version: ["3.12"]
         allow-prereleases: [false]
         unsafe-pyo3-skip-version-check: [0]
@@ -97,7 +97,7 @@ jobs:
 
       - uses: dtolnay/rust-toolchain@7b1c307e0dcbda6122208f10795a713336a9b35a
         with:
-          toolchain: "1.73.0"
+          toolchain: "stable"
 
       - uses: Swatinem/rust-cache@23bce251a8cd2ffc3c1075eaa2367cf899916d84  # 2.7.3
       - run: python3 -m pip install nox