chore: update ubuntu version on circleci

The default 22.04 uses older libvips (8.12.1) than local development (8.14.1), causing subtle rendering differences.
24.04 happens to use even newer (8.15.1), lets see how the differences look like there

.github/workflows/main.yml

@@ -28,15 +28,16 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
   tests:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         ruby: ['2.7', '3.0', '3.1', '3.2', '3.3']
     name: install dependencies and run tests
     steps:
       - name: install image processing dependencies
         run: |
-          sudo apt-get install -yqq liblcms2-utils libglib2.0-dev libgtk2.0-dev libgdk-pixbuf2.0-dev libvips
+          sudo apt-get update \
+          && sudo apt-get install -yqq liblcms2-utils libglib2.0-dev libgtk2.0-dev libgdk-pixbuf2.0-dev libvips
       - name: checkout repo
         uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871 # v4.2.1
       - name: unlock the gem versions