[native] Add disk usage output to CI

The Linux debug build consumes a lot of disk space and occasionally
the worker can run out of disk space. This adds some more information on
the disk space consumption and availability to keep an eye on it.

.github/workflows/prestocpp-linux-build.yml

@@ -46,6 +46,9 @@ jobs:
           find . -name tests | xargs rm -r
           find . -name test | xargs rm -rf
 
+      - name: Disk space consumption before build
+        run: df
+
       - name: Build engine
         run: |
           source /opt/rh/gcc-toolset-12/enable
@@ -72,6 +75,9 @@ jobs:
             -DMAX_LINK_JOBS=4
           ninja -C _build/debug -j 4
 
+      - name: Disk space consumption after build
+        run: df
+
       - name: Ccache after
         run: ccache -s