feat: Android improvements needed for building NumPy and related packages (#2695)

* Use auditwheel on Android

* Add auditwheel command to defaults

* pkgconfig fixes

* Pre-import ctypes before monkey-patching in _cross_venv

* Set PKG_CONFIG and PKG_CONFIG_RELOCATE_PATHS variables

* Initial attempt at using mzakharo/android-gfortran

* Switch to using termux/ndk-toolchain-clang-with-flang

* Move PKG_CONFIG variables from build_env to android_env

* Simplify flang installation

* Add cross build files for NumPy

* Add ldpaths entry for libomp

* Add `--rm` to docker command line

* Make Rust and Fortran shims consistent

* Update documentation

* Default to API level 24 on all Python versions

* Clarify comments

* Cleanups

* Fix tests:
* Set up Android env after installing pkgconf
* Add tests for successfully using an older API level
* Previous commit's auditwheel failure is fixed in the auditwheel PR

* Update how-it-works diagram

* Add tests for repair errors

* Add more repair tests

* Add test for Meson and Fortran

* Add test for cross build files

* Improve test_api_level error message

* Add xbuild-files option

* use pypa/auditwheel@main

* Remove dependencies which are no longer needed

* Fix README

* Update to auditwheel 6.7.0

* Fix compatibility with pkgconf 2.5.1.post2

* Documentation clarifications

Co-authored-by: Joe Rickerby <joerick@mac.com>

* Fortran shim improvements

* Add Jinja variables to new_meson_project

* Update run_example_ci_configs for changed new_meson_project signature

* Add missing dependency to run_example_ci_configs

---------

Co-authored-by: mayeut <mayeut@users.noreply.github.com>
Co-authored-by: Joe Rickerby <joerick@mac.com>

cibuildwheel/resources/constraints-python313.txt

@@ -10,6 +10,8 @@ attrs==26.1.0
     # via
     #   cattrs
     #   requests-cache
+auditwheel==6.7.0
+    # via -r cibuildwheel/resources/constraints.in
 build==1.5.0
     # via -r cibuildwheel/resources/constraints.in
 cattrs==26.1.0
@@ -43,21 +45,28 @@ mdurl==0.1.2
 packaging==26.2
     # via
     #   abi3audit
+    #   auditwheel
     #   build
     #   delocate
+patchelf==0.17.2.4
+    # via -r cibuildwheel/resources/constraints.in
 pefile==2024.8.26
     # via
     #   abi3audit
     #   delvewheel
 pip==26.1.1
     # via -r cibuildwheel/resources/constraints.in
+pkgconf==2.5.1.post2
+    # via -r cibuildwheel/resources/constraints.in
 platformdirs==4.9.6
     # via
     #   python-discovery
     #   requests-cache
     #   virtualenv
 pyelftools==0.32
-    # via abi3audit
+    # via
+    #   abi3audit
+    #   auditwheel
 pygments==2.20.0
     # via rich
 pyproject-hooks==1.2.0