build: Always build conformance tests with debug symbols
build: Always build conformance tests with debug symbols

Having the conformance test suite build without debug symbols doesn't
make any sense.

djdeath/clutter-multithreaded,djdeath/clutter,spatulasnout/clutter,GNOME/clutter,ebassi/clutter,dlespiau/clutter,heysion/clutter-clone,djdeath/clutter-android,collects/clutter,Distrotech/clutter,collects/clutter,djdeath/clutter-android,nobled/clutter,Distrotech/clutter,heysion/clutter-clone,rkudiyarov/clutter_osx,dlespiau/clutter,djdeath/clutter,heysion/clutter-clone,kerrickstaley/clutter-vala,GNOME/clutter,GNOME/clutter,heysion/clutter-clone,Distrotech/clutter,rkudiyarov/clutter_osx,spatulasnout/clutter,djdeath/clutter-android,djdeath/clutter,jigpu/clutter,spatulasnout/clutter,djdeath/clutter,ebassi/clutter,djdeath/clutter-multithreaded,Distrotech/clutter,spatulasnout/clutter,collects/clutter,rkudiyarov/clutter_osx,djdeath/clutter-android,nobled/clutter,Distrotech/clutter,nobled/clutter,collects/clutter,jigpu/clutter,jigpu/clutter,kerrickstaley/clutter-vala,djdeath/clutter-multithreaded,GNOME/clutter,collects/clutter,ebassi/clutter,GNOME/clutter,dlespiau/clutter,jigpu/clutter,Distrotech/clutter,djdeath/clutter,jigpu/clutter,jigpu/clutter,spatulasnout/clutter,djdeath/clutter-multithreaded,djdeath/clutter,kerrickstaley/clutter-vala,rkudiyarov/clutter_osx,ebassi/clutter,ebassi/clutter,djdeath/clutter-android,kerrickstaley/clutter-vala,heysion/clutter-clone