[BUG]: pip installed pybind11 not picked up by CMake

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Problem description

If I install pybind11 via pip, then CMake cannot find it.

Reproducible example code

deleteme$ python3.9 -m venv .
deleteme$ . bin/activate
deleteme$ python3 -m pip install pybind11
Collecting pybind11
  Using cached pybind11-2.8.1-py2.py3-none-any.whl (208 kB)
Installing collected packages: pybind11
Successfully installed pybind11-2.8.1
deleteme$ cat CMakeLists.txt
cmake_minimum_required(VERSION 3.21.1)
project(Reproduce)
find_package(pybind11 REQUIRED)
deleteme$ mkdir build && cd build
build$ cmake --version
cmake version 3.21.1
build$ cmake ../
CMake Error at CMakeLists.txt:5 (find_package):
  By not providing "Findpybind11.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "pybind11",
  but CMake did not find one.

  Could not find a package configuration file provided by "pybind11" with any
  of the following names:

    pybind11Config.cmake
    pybind11-config.cmake

  Add the installation prefix of "pybind11" to CMAKE_PREFIX_PATH or set
  "pybind11_DIR" to a directory containing one of the above files.  If
  "pybind11" provides a separate development package or SDK, be sure it has
  been installed.


-- Configuring incomplete, errors occurred!

Start by reproducing the failure with the provided Python 3.9 virtual environment, pip install command, and CMakeLists.txt containing find_package(pybind11 REQUIRED). Inspect how the pip-installed package exposes its CMake configuration and verify that configuring the example succeeds without manual path settings.