python3-*: Update recipes with pytest ptests to use the new ptest-python-pytest class

The newly added ptest-python-pytest removes duplication for:
  1. Copying pytest files to the ptest directory
  2. Adding standard pytest dependencies
  3. Adding a common run-ptest script using pytest

(From OE-Core rev: 8d84d9e19b9292b1863921611924714d77c41d21)

Signed-off-by: Derek Straka <derek@asterius.io>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/python/python3-xmltodict_0.14.2.bb

@@ -9,11 +9,7 @@ PYPI_PACKAGE = "xmltodict"
 
 BBCLASSEXTEND = "native nativesdk"
 
-inherit pypi setuptools3 ptest
-
-SRC_URI += " \
-	file://run-ptest \
-"
+inherit pypi setuptools3 ptest-python-pytest
 
 RDEPENDS:${PN} += " \
 	python3-core \
@@ -21,11 +17,3 @@ RDEPENDS:${PN} += " \
 	python3-io \
 "
 
-RDEPENDS:${PN}-ptest += " \
-	python3-pytest \
-"
-
-do_install_ptest() {
-	install -d ${D}${PTEST_PATH}/tests
-	cp -rf ${S}/tests/* ${D}${PTEST_PATH}/tests/
-}