Fix CI/CD fail by installing ImageMagick on runner

This commit addresses an issue where CI/CD jobs fail due to the removal of
`imagemagick` from GitHub's preinstalled software list for Ubuntu
runners. As a result, commands relying on `imagemagick` were not found.

To resolve this, the commit installs `imagemagick` across all platforms
(Linux, macOS, and Windows). This safeguards against future changes to
the preinstalled software list on GitHub runners.

This commit also centralizes installing of ImageMagick as its own action
for reusability.

.github/workflows/checks.scripts.yaml

@@ -9,16 +9,15 @@ jobs:
     runs-on: ${{ matrix.os }}-latest
     strategy:
       matrix:
-        os: [ macos, ubuntu, windows ]
+        os: [macos, ubuntu, windows]
       fail-fast: false # Still interested to see results from other combinations
     steps:
       -
         name: Checkout
         uses: actions/checkout@v4
       -
-        name: Install ImageMagick on macOS
-        if: matrix.os == 'macos'
-        run: brew install imagemagick
+        name: Install ImageMagick
+        uses: ./.github/actions/install-imagemagick
       -
         name: Setup node
         uses: ./.github/actions/setup-node