Update Android test-command handling (#2590)

* Update Android test-command handling

* Update to Python 3.13.8

* Update documentation and tests

* Deal with `sysconfig.get_config_var("exec_prefix")` changing in Python 3.14, and add cross venv tests

* Allow test commands starting with `python3`

* test-command cleanups

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

README.md

@@ -70,7 +70,7 @@ Usage
 <sup>² [Uses cross-compilation](https://cibuildwheel.pypa.io/en/stable/faq/#windows-arm64). It is not possible to test `arm64` on this CI platform.</sup><br>
 <sup>³ Requires a macOS runner; runs tests on the simulator for the runner's architecture. </sup><br>
 <sup>⁴ Building for Android requires the runner to be Linux x86_64, macOS ARM64 or macOS x86_64. Testing has [additional requirements](https://cibuildwheel.pypa.io/en/stable/platforms/#android).</sup><br>
-<sup>⁵ The `macos-15` and `macos-latest` images are [incompatible with cibuildwheel at this time](platforms/#ios-system-requirements)</sup><br> when building iOS wheels.
+<sup>⁵ The `macos-15` and `macos-latest` images are [incompatible with cibuildwheel at this time](https://cibuildwheel.pypa.io/en/stable/platforms/#ios-system-requirements) when building iOS wheels.</sup><br>
 
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