Fix Ubuntu CI by extracting latest Tag instead of organization variable

.github/workflows/ubuntu.yml

@@ -16,18 +16,36 @@ jobs:
       fail-fast: false
       matrix:
         distro: [focal, jammy, noble]
-    container:
-      image: ghcr.io/tesseract-robotics/tesseract:${{ matrix.distro }}-${{ vars.TESSERACT_DOCKER_TAG }}
-      env:
-        CCACHE_DIR: "$GITHUB_WORKSPACE/${{ matrix.distro }}/.ccache"
-        DEBIAN_FRONTEND: noninteractive
-        TZ: Etc/UTC
+
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
         with:
           path: target_ws/src
 
+      - name: Get latest tag
+        id: get_latest_tag  # This step ID allows us to reference its outputs
+        run: |
+          latest_tag=$(git describe --tags `git rev-list --tags --max-count=1`)
+          echo "Latest tag: $latest_tag"
+
+          # Extract major and minor version from the tag
+          IFS='.' read -r major minor patch <<< "$latest_tag"
+          echo "Major: $major"
+          echo "Minor: $minor"
+
+          # Set as output variables
+          echo "::set-output name=major::$major"
+          echo "::set-output name=minor::$minor"
+
+    container:
+      image: ghcr.io/tesseract-robotics/tesseract:${{ matrix.distro }}-${{ steps.get_latest_tag.outputs.major }}.${{ steps.get_latest_tag.outputs.minor }}
+      env:
+        CCACHE_DIR: "$GITHUB_WORKSPACE/${{ matrix.distro }}/.ccache"
+        DEBIAN_FRONTEND: noninteractive
+        TZ: Etc/UTC
+
+    steps:
       - name: Build and Tests
         uses: tesseract-robotics/colcon-action@v8
         with: