[favoriteproxytest] Link against KConfig

This happens to work because of transitive linkage, but we better not
rely on that.
2 jobs for !56 with work/linkconfig in 18 minutes and 33 seconds (queued for 48 minutes and 35 seconds)
latest detached
Status Job ID Name Coverage
  Build
failed #99103
build_clazy_clang_tidy

00:04:55

passed #99102
linux kf5-qt5 qt5.15

00:13:37

1.0%
 
Name Stage Failure
failed
build_clazy_clang_tidy Build
make[2]: *** [src/shared/CMakeFiles/akonadi_shared.dir/build.make:121: src/shared/CMakeFiles/akonadi_shared.dir/akremotelog.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:2655: src/shared/CMakeFiles/akonadi_shared.dir/all] Error 2
make: *** [Makefile:160: all] Error 2
Uploading artifacts for failed job
Uploading artifacts...
WARNING: build/clang-tidy-report.xml: no matching files
ERROR: No files to upload
Cleaning up file based variables
ERROR: Job failed: exit code 1