add aarch64 support for linux

comes from the docs in https://cibuildwheel.pypa.io/en/stable/faq/#emulation

.github/workflows/cibuildwheel.yml

@@ -17,6 +17,9 @@ jobs:
       CIBW_BEFORE_BUILD: "pip install --only-binary :all: -r requirements.txt"
       # There are/were no numpy wheels for these:
       CIBW_SKIP: pp37-* pp38-* pp39-* pp310-* cp39-manylinux_i686 cp310-manylinux_i686 cp311-manylinux_i686 cp312-manylinux_i686 *-musllinux_*
+      # configure cibuildwheel to build native archs ('auto'), and some
+      # emulated ones
+      CIBW_ARCHS_LINUX: auto aarch64
       # Quick test with C code using NumPy C API:
       CIBW_TEST_COMMAND: "python {package}/Tests/test_Cluster.py"
 
@@ -26,6 +29,12 @@ jobs:
           fetch-depth: 0  # Optional
           submodules: true  # Optional, use if you have submodules
 
+      - name: Set up QEMU
+        if: runner.os == 'Linux'
+        uses: docker/setup-qemu-action@v3
+        with:
+          platforms: all
+
       - name: Checkout tag/commit
         run: |
           git submodule update --init biopython