python3-setuptools: Add back accidentally dropped RDEPENDS

This was accidentally removed in a previous commit. Due to improvements
in the core, we can now just add it as a normal RDEPENDS along with the
others as the native case no longer causes issues.

(From OE-Core rev: 83d8b469750d7917376abb4d34f7797ee0f75267)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/python/python3-setuptools_51.0.0.bb

@@ -28,6 +28,7 @@ RDEPENDS_${PN} = "\
   ${PYTHON_PN}-netserver \
   ${PYTHON_PN}-numbers \
   ${PYTHON_PN}-pickle \
+  ${PYTHON_PN}-pkg-resources \
   ${PYTHON_PN}-pkgutil \
   ${PYTHON_PN}-plistlib \
   ${PYTHON_PN}-shell \