Disable build for ros foxy

Signed-off-by: Beniamino Pozzan <[email protected]>

.github/workflows/build.yml

@@ -11,18 +11,6 @@ defaults:
     shell: bash
 
 jobs:
-  focal:
-    name: "Build on Ubuntu Focal"
-    runs-on: ubuntu-20.04
-    steps:
-      - uses: actions/checkout@v4
-      - uses: ros-tooling/[email protected]
-        with:
-          required-ros-distributions: foxy
-      - uses: ros-tooling/[email protected]
-        with:
-          package-name: px4_msgs
-          target-ros2-distro: foxy
   jammy:
     name: "Build on Ubuntu Jammy"
     runs-on: ubuntu-22.04