ci(compile-ubuntu): replace quick_check with targeted SITL and NuttX builds

Replace make quick_check with two explicit build targets:
px4_sitl_default (validates native SITL toolchain) and
px4_fmu-v5_default (validates NuttX cross-compile toolchain).

quick_check built four targets: px4_sitl_test, px4_fmu-v5_default,
tests, and check_format. The tests and check_format targets are
redundant with checks.yml which already runs them on 8cpu RunsOn
with ccache.

The purpose of this workflow is to validate that PX4 builds from a
fresh ubuntu.sh install on both Ubuntu 22.04 and 24.04, not to run
tests or check formatting. Two targeted builds are sufficient.

px4_fmu-v5_default is kept as the hardware target (same as
quick_check) since it builds with the arm-none-eabi-gcc version
that ubuntu.sh installs on both 22.04 and 24.04.

Expected duration drop from 16-17 min to 6-8 min per matrix entry.

Signed-off-by: Ramon Roche <mrpollo@gmail.com>

.github/workflows/compile_ubuntu.yml

@@ -63,8 +63,11 @@ jobs:
           cache-key-prefix: ccache-ubuntu-${{ matrix.version }}
           max-size: 200M
 
-      - name: Make Quick Check
-        run: make quick_check
+      - name: Build px4_sitl_default
+        run: make px4_sitl_default
+
+      - name: Build px4_fmu-v5_default
+        run: make px4_fmu-v5_default
 
       - uses: ./.github/actions/save-ccache
         if: always()