Allow build armv6l for musllinux

[andypost]

Release 1.11.4 added support for the armv6l arch but upgrading the package for Alpinelinux from 1.9.6 to 1.11.5 caused build failure for the arch so I have to patch

The tail of log

    📦 Including files matching "pyo3_mixed/assets/*"
    📦 Built source distribution to /tmp/.tmpfacQKA/dist/pyo3_mixed-2.1.5.tar.gz
    🍹 Building a mixed python/rust project
    🔗 Found pyo3 bindings
    🐍 Found CPython 3.12 at /usr/bin/python3
    Cause: Your library is not musllinux_1_2 compliant because it has unsupported architecture: armv6l
    Cause: Error ensuring musllinux_1_2 compliance
    thread 'unreadable_dir' (21096) panicked at tests/run.rs:610:5:
    Error ensuring musllinux_1_2 compliance
    note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
        PASS [  42.327s] (123/126) maturin::run pyo3_source_date_epoch
        PASS [  42.596s] (124/126) maturin::run pep517_editable_profile
        PASS [  43.551s] (125/126) maturin::run integration_workspace_inverted_order
        PASS [  50.646s] (126/126) maturin::run pep517_default_profile
────────────
     Summary [ 383.739s] 126 tests run: 125 passed (17 slow), 1 failed, 12 skipped
        FAIL [  40.011s] (122/126) maturin::run unreadable_dir
error: test run failed

[konstin]

This file is vendored from https://github.com/pypa/auditwheel/blob/main/src/auditwheel/policy/musllinux-policy.json, we shouldn't diverge from it. Maybe we need to update it upstream?

[andypost]

Looks like it was skipped on initial compatibility pypa/auditwheel#315 (comment)

[konstin]

armv6l is kind of an odd platform cause pypi supports it as linux_armv6l. We need to fix the arm-unknown-linux-musleabihf target (sorry for breaking it), but I think we need to do something different about tagging it.