python: Drop ${PYTHON_PN}

python 2 is gone and we don't need the abstraction now, drop the remaining usage
of this variable.

The definition in python3-dir.bbclass is left for now for other layers.

(From OE-Core rev: b566b1e32c7993d1ab7795562f648e52ce186a70)

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

meta/recipes-devtools/python/python3-license-expression_30.2.0.bb

@@ -8,14 +8,14 @@ SRC_URI[sha256sum] = "599928edd995c43fc335e0af342076144dc71cb858afa1ed9c1c30c4e8
 
 inherit pypi ptest python_setuptools_build_meta
 
-DEPENDS += "${PYTHON_PN}-setuptools-scm-native"
+DEPENDS += "python3-setuptools-scm-native"
 
 RDEPENDS:${PN} += "\
-    ${PYTHON_PN}-booleanpy \
-    ${PYTHON_PN}-core \
-    ${PYTHON_PN}-json \
-    ${PYTHON_PN}-stringold \
-    ${PYTHON_PN}-logging \
+    python3-booleanpy \
+    python3-core \
+    python3-json \
+    python3-stringold \
+    python3-logging \
 "
 
 BBCLASSEXTEND = "native nativesdk"
@@ -25,8 +25,8 @@ SRC_URI += " \
 "
 
 RDEPENDS:${PN}-ptest += " \
-	${PYTHON_PN}-pytest \
-	${PYTHON_PN}-unittest-automake-output \
+	python3-pytest \
+	python3-unittest-automake-output \
 "
 
 do_install_ptest() {