build: Fix searching libdnf header files

Previously, a search path for in-source libdnf header files was listed
in the middle of paths for other dependencies. That caused swig to
generate bindings from system header files, possible incompatible with
the in-source library, leading to a build failure like this:

    cd /home/test/fedora/libdnf/libdnf-0.74.0-build/libdnf-0.74.0/build-py3/bindings/python && /usr/bin/cmake -E env SWIG_LIB=/usr/share/swig/4.3.1 /usr/bin/swig -python -DSWIGWORDSIZE64 -DLIBDNF_UNSTABLE_API -outdir /home/test/fedora/libdnf/libdnf-0.74.0-build/libdnf-0.74.0/build-py3/bindings/python -c++ -interface _repo -I/usr/include/gio-unix-2.0 -I/usr/include -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/sysprof-6 -I/usr/include/json-c -I/usr/include/libxml2 -I/home/test/fedora/libdnf/libdnf-0.74.0-build/libdnf-0.74.0 -I/home/test/fedora/libdnf/libdnf-0.74.0-build/libdnf-0.74.0/libdnf/utils -I/usr/include/python3.14 -o /home/test/fedora/libdnf/libdnf-0.74.0-build/libdnf-0.74.0/build-py3/bindings/python/CMakeFiles/_repo.dir/repoPYTHON_wrap.cxx /home/test/fedora/ libdnf/libdnf-0.74.0-build/libdnf-0.74.0/bindings/swig/repo.i
    [...]
    /home/test/fedora/libdnf/libdnf-0.74.0-build/libdnf-0.74.0/build-py3/bindings/python/CMakeFiles/_conf.dir/confPYTHON_wrap.cxx: In function ‘PyObject* _wrap_ConfigMain_usr_drift_protected_paths(PyObject*, PyObject*)’:
    /home/test/fedora/libdnf/libdnf-0.74.0-build/libdnf-0.74.0/build-py3/bindings/python/CMakeFiles/_conf.dir/confPYTHON_wrap.cxx:23913:54: error: ‘class libdnf::ConfigMain’ has no member named ‘usr_drift_protected_paths’
    23913 |       result = (libdnf::OptionStringList *) &(arg1)->usr_drift_protected_paths();
	  |                                                      ^~~~~~~~~~~~~~~~~~~~~~~~~

This patch fixes the header search path order by placing both paths to
the in-source header files at the very first place.

Resolve: #1716

Author: ppisar

CMakeLists.txt

@@ -42,6 +42,9 @@ option(WITH_TESTS "Enables unit tests" ON)
 option(WITH_SANITIZERS "Build with address, leak and undefined sanitizers (DEBUG ONLY)" OFF)
 
 
+# always place our header files before system ones
+include_directories(${CMAKE_SOURCE_DIR} libdnf/utils/)
+
 # load pkg-config first; it's required by other modules
 find_package(PkgConfig REQUIRED)
 if(APPLE)
@@ -69,9 +72,6 @@ pkg_check_modules(RPM REQUIRED rpm>=4.15.0)
 pkg_check_modules(SMARTCOLS REQUIRED smartcols)
 pkg_check_modules(SQLite3 REQUIRED sqlite3)
 
-# always enable linking with libdnf utils
-include_directories(${CMAKE_SOURCE_DIR} libdnf/utils/)
-
 if (WITH_ZCHUNK)
     pkg_check_modules(ZCHUNKLIB zck>=0.9.11 REQUIRED)
     set (CMAKE_CXX_FLAGS          "${CMAKE_CXX_FLAGS} -DWITH_ZCHUNK")