Drop library directories from install to reduce size (#1688)

The libraries are added when we include deps via add_subdirectory.
There isn't a simple way to ask CMake to not install them. A clean
way would be to use components, but our cmake is not there at the
moment.

docker-build/scripts/04_install.sh

@@ -1,3 +1,11 @@
 cd "${BUILD_DIR}"
 
 make install
+
+# Manually remove the lib, include and share directories coming
+# from the GNUInstallDirs. Unfortunately it's not possible to
+# easily disable in CMake all installation targets exported when
+# using add_subdirectory so we drop them from installation manually.
+# This is done to heavily reduce the resulting install size.
+cd "${INSTALL_DIR}"
+rm -rf lib include share