meta-oniro-staging/layer.conf: Drop oniro-core dependency

There is no need for this dependency as this layer doesn't rely on
oniro-core.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-oniro-staging/conf/layer.conf

@@ -27,6 +27,5 @@ BBFILE_PRIORITY_oniro-staging = "5"
 
 LAYERDEPENDS_oniro-staging = " \
     core \
-    oniro-core \
     "
 LAYERSERIES_COMPAT_oniro-staging = "dunfell"