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-pymysql_1.1.0.bb

@@ -16,4 +16,4 @@ inherit pypi python_setuptools_build_meta
 UPSTREAM_CHECK_URI = "https://pypi.python.org/pypi/pymysql/"
 UPSTREAM_CHECK_REGEX = "/pymysql/(?P<pver>(\d+[\.\-_]*)+)"
 
-RDEPENDS:${PN} += "${PYTHON_PN}-cryptography"
+RDEPENDS:${PN} += "python3-cryptography"