resync pybind11 with upstream

Author: mattip

.github/workflows/pybind11.yml

@@ -37,17 +37,6 @@ jobs:
         - 'pypy-3.10-nightly'
         - 'pypy-3.11-nightly'
 
-        # Items in here will either be added to the build matrix (if not
-        # present), or add new keys to an existing matrix element if all the
-        # existing keys match.
-        #
-        # We support an optional key: args, for cmake args
-        include:
-          - runs-on: ubuntu-latest
-            python: 'pypy-3.9-nightly'
-            args: >
-              -DPYBIND11_FINDPYTHON=ON
-
     name: "pybind11 ${{ matrix.python }} • ${{ matrix.runs-on }} x64 ${{ matrix.args }}"
     runs-on: ${{ matrix.runs-on }}
 
@@ -75,7 +64,7 @@ jobs:
 
     - name: Cache wheels
       if: runner.os == 'macOS'
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         # This path is specific to macOS - we really only need it for PyPy NumPy wheels
         # See https://github.com/actions/cache/blob/master/examples.md#python---pip
@@ -93,6 +82,8 @@ jobs:
       run: python -m pip install pytest-github-actions-annotate-failures
 
     # First build - C++11 mode and inplace
+    # More-or-less randomly adding -DPYBIND11_SIMPLE_GIL_MANAGEMENT=ON here
+    # (same for PYBIND11_NUMPY_1_ONLY, but requires a NumPy 1.x at runtime).
     - name: Configure C++11 ${{ matrix.args }}
       run: >
         cmake -S . -B .
@@ -113,7 +104,7 @@ jobs:
       run: cmake --build . --target pytest -j 2
 
     - name: C++11 tests
-      run: cmake --build .  --target cpptest -j 2
+      run: cmake --build . --target cpptest -j 2
 
     - name: Interface test C++11
       run: cmake --build . --target test_cmake_build
@@ -122,6 +113,8 @@ jobs:
       run: git clean -fdx
 
     # Second build - C++17 mode and in a build directory
+    # More-or-less randomly adding -DPYBIND11_SIMPLE_GIL_MANAGEMENT=OFF here.
+    # (same for PYBIND11_NUMPY_1_ONLY, but requires a NumPy 1.x at runtime).
     - name: Configure C++17
       run: >
         cmake -S . -B build2
@@ -153,7 +146,6 @@ jobs:
         -DDOWNLOAD_EIGEN=ON
         -DCMAKE_CXX_STANDARD=17
         -DPYBIND11_INTERNALS_VERSION=10000000
-        "-DPYBIND11_TEST_OVERRIDE=test_call_policies.cpp;test_gil_scoped.cpp;test_thread.cpp"
         ${{ matrix.args }}
 
     - name: Build (unstable ABI)