Avoid spurious libgcc-s1 Debian package dependency

Do not add a strict dependency on gcc, which in a GitHub container isn't
necessarily the same version as in a pristine Ubuntu system.

Fixes: #5875

Author: tautschnig

.github/workflows/pull-request-checks.yaml

@@ -375,6 +375,7 @@ jobs:
         run: | 
           sudo apt-get update
           sudo apt-get install --no-install-recommends -y g++ flex bison cmake ninja-build maven jq libxml2-utils dpkg-dev ccache
+          sudo apt-get --purge remove -s libgcc-s1
       - name: Prepare ccache
         uses: actions/cache@v2
         with:

cmake/packaging.cmake

@@ -25,7 +25,8 @@ set(CPACK_PACKAGE_RESOURCE_FILE_README "${CMAKE_CURRENT_SOURCE_DIR}/README.md")
 set(CPACK_DEBIAN_PACKAGE_SHLIBDEPS YES)
 
 # In addition, we depend on gcc for preprocessing
-set(CPACK_DEBIAN_PACKAGE_DEPENDS gcc)
+set(CPACK_DEBIAN_PACKAGE_RECOMMENDS gcc)
+set(CPACK_DEBIAN_PACKAGE_DEBUG YES)
 
 # For windows we need to set up product and update GUID
 # See: https://docs.microsoft.com/en-us/windows/win32/msi/productcode