[CI]: Bump actions/download-artifact from 4.1.9 to 4.2.1

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4.1.9 to 4.2.1.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v4.1.9...v4.2.1)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/test.yml

@@ -42,13 +42,13 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Get OpenAssetIO
-        uses: actions/download-artifact@v4.1.9
+        uses: actions/download-artifact@v4.2.1
         with:
           name: OpenAssetIO Build
           path: ${{ github.workspace }}/openassetio-build
 
       - name: Get OpenAssetIO-MediaCreation
-        uses: actions/download-artifact@v4.1.9
+        uses: actions/download-artifact@v4.2.1
         with:
           name: OpenAssetIO MediaCreation Build
           path: ${{ github.workspace }}/openassetio-mediacreation-build
@@ -86,7 +86,7 @@ jobs:
           git config --system --add safe.directory $(pwd)
 
       - name: Get OpenAssetIO-MediaCreation
-        uses: actions/download-artifact@v4.1.9
+        uses: actions/download-artifact@v4.2.1
         with:
           name: OpenAssetIO MediaCreation Build
           path: ./openassetio-mediacreation-build
@@ -130,7 +130,7 @@ jobs:
           git config --system --add safe.directory $(pwd)
 
       - name: Get OpenAssetIO
-        uses: actions/download-artifact@v4.1.9
+        uses: actions/download-artifact@v4.2.1
         with:
           name: OpenAssetIO Build
           path: ./openassetio-build