checks: set pipelines to NULL state in parse-launch unit test
checks: set pipelines to NULL state in parse-launch unit test

Fixes timeouts in gst_task_cleanup_all().

lubosz/gstreamer,ylatuya/gstreamer,ahmedammar/platform_external_gst_gstreamer,ensonic/gstreamer,shelsonjava/gstreamer,jpxiong/gstreamer,krieger-od/gstreamer,ensonic/gstreamer,krieger-od/gstreamer,mparis/gstreamer,drothlis/gstreamer,jpakkane/gstreamer,krichter722/gstreamer,ensonic/gstreamer,magcius/gstreamer,mrchapp/gstreamer,Distrotech/gstreamer,lovebug356/gstreamer,jpakkane/gstreamer,ylatuya/gstreamer,cfoch/gstreamer,mparis/gstreamer,krichter722/gstreamer,magcius/gstreamer,collects/gstreamer,Distrotech/gstreamer,cfoch/gstreamer,cfoch/gstreamer,Lachann/gstreamer,collects/gstreamer,ylatuya/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,StreamUtils/gstreamer,StreamUtils/gstreamer,cablelabs/gstreamer,shelsonjava/gstreamer,jpakkane/gstreamer,drothlis/gstreamer,jpxiong/gstreamer,magcius/gstreamer,mrchapp/gstreamer,drothlis/gstreamer,Lachann/gstreamer,shelsonjava/gstreamer,krieger-od/gstreamer,cablelabs/gstreamer,lubosz/gstreamer,mparis/gstreamer,jpakkane/gstreamer,centricular/gstreamer,jpxiong/gstreamer,centricular/gstreamer,Lachann/gstreamer,justinjoy/gstreamer,ensonic/gstreamer,lovebug356/gstreamer,lovebug356/gstreamer,ylatuya/gstreamer,jpxiong/gstreamer,surround-io/gstreamer,cfoch/gstreamer,Distrotech/gstreamer,ahmedammar/platform_external_gst_gstreamer,magcius/gstreamer,ylatuya/gstreamer,lovebug356/gstreamer,ahmedammar/platform_external_gst_gstreamer,Distrotech/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,surround-io/gstreamer,lubosz/gstreamer,justinjoy/gstreamer,drothlis/gstreamer,Lachann/gstreamer,lubosz/gstreamer,ahmedammar/platform_external_gst_gstreamer,drothlis/gstreamer,krieger-od/gstreamer,justinjoy/gstreamer,mparis/gstreamer,shelsonjava/gstreamer,Distrotech/gstreamer,justinjoy/gstreamer,mrchapp/gstreamer,cfoch/gstreamer,krieger-od/gstreamer,lubosz/gstreamer,surround-io/gstreamer,ensonic/gstreamer,StreamUtils/gstreamer,cablelabs/gstreamer,centricular/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,centricular/gstreamer,krichter722/gstreamer,centricular/gstreamer,justinjoy/gstreamer,magcius/gstreamer,StreamUtils/gstreamer,collects/gstreamer,mrchapp/gstreamer,ahmedammar/platform_external_gst_gstreamer,mrchapp/gstreamer,lovebug356/gstreamer,surround-io/gstreamer,Lachann/gstreamer,collects/gstreamer,surround-io/gstreamer,jpakkane/gstreamer,collects/gstreamer,cablelabs/gstreamer,mparis/gstreamer