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/options.py

@@ -120,6 +120,7 @@ class BuildOptions:
     before_all: str
     before_build: str | None
     xbuild_tools: list[str] | None
+    xbuild_files: dict[str, list[str]]
     repair_command: str
     manylinux_images: dict[str, str] | None
     musllinux_images: dict[str, str] | None
@@ -772,6 +773,14 @@ class Options:
             if xbuild_tools == ["\u0000"]:
                 xbuild_tools = None
 
+            xbuild_files = parse_key_value_string(
+                self.reader.get(
+                    "xbuild-files",
+                    option_format=ShlexTableFormat(sep="; ", pair_sep=":", allow_merge=False),
+                ),
+                kw_arg_names=["*"],
+            )
+
             test_sources = shlex.split(
                 self.reader.get(
                     "test-sources", option_format=ListFormat(sep=" ", quote=shlex.quote)
@@ -925,6 +934,7 @@ class Options:
                 before_all=before_all,
                 build_verbosity=build_verbosity,
                 xbuild_tools=xbuild_tools,
+                xbuild_files=xbuild_files,
                 repair_command=repair_command,
                 environment=environment,
                 dependency_constraints=dependency_constraints,