Pin our GitHub Actions dependencies (#18255)

After the [recent supply chain attack](https://www.wiz.io/blog/new-github-action-supply-chain-attack-reviewdog-action-setup)
in `tj-actions/changed-files` and actions based on it, it's become clear
that relying on git tags to pin our dependencies is not enough (as tags
can simply be replaced). Therefore we need to switch to hashes.

Dependabot should continue to update these dependencies for us.

Best reviewed commit-by-commit. Though if CI passes, we're *probably*
fine.

.github/workflows/release-artifacts.yml

@@ -27,8 +27,8 @@ jobs:
     name: "Calculate list of debian distros"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           python-version: '3.x'
       - id: set-distros
@@ -55,18 +55,18 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           path: src
 
       - name: Set up Docker Buildx
         id: buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3.10.0
         with:
           install: true
 
       - name: Set up docker layer caching
-        uses: actions/cache@v4
+        uses: actions/cache@d4323d4df104b026a6aa633fdb11d772146be0bf # v4.2.2
         with:
           path: /tmp/.buildx-cache
           key: ${{ runner.os }}-buildx-${{ github.sha }}
@@ -74,7 +74,7 @@ jobs:
             ${{ runner.os }}-buildx-
 
       - name: Set up python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           python-version: '3.x'
 
@@ -101,7 +101,7 @@ jobs:
           echo "ARTIFACT_NAME=${DISTRO#*:}" >> "$GITHUB_OUTPUT"
 
       - name: Upload debs as artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@4cec3d8aa04e39d1a68397de0c4cd6fb9dce8ec1 # v4.6.1
         with:
           name: debs-${{ steps.artifact-name.outputs.ARTIFACT_NAME }}
           path: debs/*
@@ -130,9 +130,9 @@ jobs:
             arch: aarch64
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           # setup-python@v4 doesn't impose a default python version. Need to use 3.x
           # here, because `python` on osx points to Python 2.7.
@@ -143,7 +143,7 @@ jobs:
 
       - name: Set up QEMU to emulate aarch64
         if: matrix.arch == 'aarch64'
-        uses: docker/setup-qemu-action@v3
+        uses: docker/setup-qemu-action@29109295f81e9208d7d86ff1c6c12d2833863392 # v3.6.0
         with:
           platforms: arm64
 
@@ -165,7 +165,7 @@ jobs:
           CARGO_NET_GIT_FETCH_WITH_CLI: true
           CIBW_ENVIRONMENT_PASS_LINUX: CARGO_NET_GIT_FETCH_WITH_CLI
 
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@4cec3d8aa04e39d1a68397de0c4cd6fb9dce8ec1 # v4.6.1
         with:
           name: Wheel-${{ matrix.os }}-${{ matrix.arch }}
           path: ./wheelhouse/*.whl
@@ -176,8 +176,8 @@ jobs:
     if: ${{ !startsWith(github.ref, 'refs/pull/') }}
 
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           python-version: '3.10'
 
@@ -186,7 +186,7 @@ jobs:
       - name: Build sdist
         run: python -m build --sdist
 
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@4cec3d8aa04e39d1a68397de0c4cd6fb9dce8ec1 # v4.6.1
         with:
           name: Sdist
           path: dist/*.tar.gz
@@ -203,7 +203,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Download all workflow run artifacts
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@b14cf4c92620c250e1c074ab0a5800e37df86765 # v4.2.0
       - name: Build a tarball for the debs
         # We need to merge all the debs uploads into one folder, then compress
         # that.
@@ -213,7 +213,7 @@ jobs:
           tar -cvJf debs.tar.xz debs
       - name: Attach to release
         # Pinned to work around https://github.com/softprops/action-gh-release/issues/445
-        uses: softprops/action-gh-release@v0.1.15
+        uses: softprops/action-gh-release@de2c0eb89ae2a093876385947365aca7b0e5f844 # v0.1.15
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with: