Remove deprecated python3-selectors from the RDEPENDS

The python3-selectors package was removed as part of the migration to the
json manifest file.  The functionality is now part of core

Signed-off-by: Derek Straka <derek@asterius.io>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-python/recipes-devtools/python/python3-whoosh_2.7.4.bb

@@ -4,5 +4,4 @@ require python-whoosh.inc
 # Requires _pydecimal.py which is in misc
 RDEPENDS_${PN} += " \
     ${PYTHON_PN}-misc \
-    ${PYTHON_PN}-selectors \
 "