Use native arm runners for building wheels (#18618)

This takes down the CI time to build wheels from 50 minutes to <10
minutes.

**It also fixes macOS ARM builds, and includes more ARM builds in
general** (we were ignoring pypy and musl before). This doesn't cost
much for us to do this, reasons for not doing this is 1. space on PyPI
and 2. keeping them 'officially' supported?

This is the list of wheels this built (`+` are the ones added):

```diff
  matrix_synapse-1.133.0-cp39-abi3-macosx_10_9_x86_64.whl
+ matrix_synapse-1.133.0-cp39-abi3-macosx_11_0_arm64.whl
  matrix_synapse-1.133.0-cp39-abi3-manylinux_2_28_aarch64.whl
  matrix_synapse-1.133.0-cp39-abi3-manylinux_2_28_x86_64.whl
+ matrix_synapse-1.133.0-cp39-abi3-musllinux_1_2_aarch64.whl
  matrix_synapse-1.133.0-cp39-abi3-musllinux_1_2_x86_64.whl
  matrix_synapse-1.133.0-pp310-pypy310_pp73-macosx_10_15_x86_64.whl
+ matrix_synapse-1.133.0-pp310-pypy310_pp73-macosx_11_0_arm64.whl
+ matrix_synapse-1.133.0-pp310-pypy310_pp73-manylinux_2_28_aarch64.whl
  matrix_synapse-1.133.0-pp310-pypy310_pp73-manylinux_2_28_x86_64.whl
  matrix_synapse-1.133.0-pp311-pypy311_pp73-macosx_10_15_x86_64.whl
+ matrix_synapse-1.133.0-pp311-pypy311_pp73-macosx_11_0_arm64.whl
+ matrix_synapse-1.133.0-pp311-pypy311_pp73-manylinux_2_28_aarch64.whl
  matrix_synapse-1.133.0-pp311-pypy311_pp73-manylinux_2_28_x86_64.whl
```

And the numbers aaaaare 🥁 

-
[before](https://github.com/element-hq/synapse/actions/runs/16072488018):
54 minutes
-
[after](https://github.com/element-hq/synapse/actions/runs/16004034949?pr=18618):
10 minutes

**Revert
[e43b0f9](e43b0f9bd1)
before merging**

.github/workflows/release-artifacts.yml

@@ -107,12 +107,15 @@ jobs:
           path: debs/*
 
   build-wheels:
-    name: Build wheels on ${{ matrix.os }} for ${{ matrix.arch }}
+    name: Build wheels on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-24.04, macos-13]
-        arch: [x86_64, aarch64]
+        os:
+          - ubuntu-24.04
+          - ubuntu-24.04-arm
+          - macos-13 # This uses x86-64
+          - macos-14 # This uses arm64
         # is_pr is a flag used to exclude certain jobs from the matrix on PRs.
         # It is not read by the rest of the workflow.
         is_pr:
@@ -122,12 +125,11 @@ jobs:
           # Don't build macos wheels on PR CI.
           - is_pr: true
             os: "macos-13"
-          # Don't build aarch64 wheels on mac.
-          - os: "macos-13"
-            arch: aarch64
+          - is_pr: true
+            os: "macos-14"
           # Don't build aarch64 wheels on PR CI.
           - is_pr: true
-            arch: aarch64
+            os: "ubuntu-24.04-arm"
 
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
@@ -141,19 +143,9 @@ jobs:
       - name: Install cibuildwheel
         run: python -m pip install cibuildwheel==3.0.0
 
-      - name: Set up QEMU to emulate aarch64
-        if: matrix.arch == 'aarch64'
-        uses: docker/setup-qemu-action@29109295f81e9208d7d86ff1c6c12d2833863392 # v3.6.0
-        with:
-          platforms: arm64
-
-      - name: Build aarch64 wheels
-        if: matrix.arch == 'aarch64'
-        run: echo 'CIBW_ARCHS_LINUX=aarch64' >> $GITHUB_ENV
-
       - name: Only build a single wheel on PR
         if: startsWith(github.ref, 'refs/pull/')
-        run: echo "CIBW_BUILD="cp39-manylinux_${{ matrix.arch }}"" >> $GITHUB_ENV
+        run: echo "CIBW_BUILD="cp39-manylinux_*"" >> $GITHUB_ENV
 
       - name: Build wheels
         run: python -m cibuildwheel --output-dir wheelhouse
@@ -161,13 +153,10 @@ jobs:
           # Skip testing for platforms which various libraries don't have wheels
           # for, and so need extra build deps.
           CIBW_TEST_SKIP: pp3*-* *i686* *musl*
-          # Fix Rust OOM errors on emulated aarch64: https://github.com/rust-lang/cargo/issues/10583
-          CARGO_NET_GIT_FETCH_WITH_CLI: true
-          CIBW_ENVIRONMENT_PASS_LINUX: CARGO_NET_GIT_FETCH_WITH_CLI
 
       - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:
-          name: Wheel-${{ matrix.os }}-${{ matrix.arch }}
+          name: Wheel-${{ matrix.os }}
           path: ./wheelhouse/*.whl
 
   build-sdist:

changelog.d/18618.misc

@@ -0,0 +1 @@
+Speed up the building of arm-based wheels in CI.

pyproject.toml

@@ -375,13 +375,10 @@ build-backend = "poetry.core.masonry.api"
 # Skip unsupported platforms (by us or by Rust).
 # See https://cibuildwheel.readthedocs.io/en/stable/options/#build-skip for the list of build targets.
 # We skip:
-#  - CPython 3.6, 3.7 and 3.8: EOLed
-#  - PyPy 3.7 and 3.8: we only support Python 3.9+
+#  - CPython and PyPy 3.8: EOLed
 #  - musllinux i686: excluded to reduce number of wheels we build.
 #    c.f. https://github.com/matrix-org/synapse/pull/12595#discussion_r963107677
-#  - PyPy on Aarch64 and musllinux on aarch64: too slow to build.
-#    c.f. https://github.com/matrix-org/synapse/pull/14259
-skip = "cp36* cp37* cp38* pp37* pp38* *-musllinux_i686 pp*aarch64 *-musllinux_aarch64"
+skip = "cp38* pp38* *-musllinux_i686"
 # Enable non-default builds.
 # "pypy" used to be included by default up until cibuildwheel 3.
 enable = "pypy"