meta-python: drop ${PYTHON_PN}

python 2 is long unsupported, so we no longer need this variable.

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-python/recipes-devtools/python/python3-progress_1.6.bb

@@ -8,8 +8,8 @@ SRC_URI[sha256sum] = "c9c86e98b5c03fa1fe11e3b67c1feda4788b8d0fe7336c2ff7d5644ccf
 inherit pypi setuptools3
 
 RDEPENDS:${PN}:class-target += " \
-    ${PYTHON_PN}-datetime \
-    ${PYTHON_PN}-math \
+    python3-datetime \
+    python3-math \
 "
 
 BBCLASSEXTEND = "native nativesdk"