classes/distutils-*: add warning of deprecation

distutils has been deprecated in Python 3.10 and will be removed in
Python 3.12 (predicted release date October 2023).

Add a warning now that recommends using the roughly equivalent
setuptools-* classes.

[YOCTO #14610]

(From OE-Core rev: 54b455049ee94c01c78b31b6c744c8e32b5b7737)

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/distutils-common-base.bbclass

@@ -23,3 +23,6 @@ FILES:${PN}-dev += "\
   ${libdir}/pkgconfig \
   ${PYTHON_SITEPACKAGES_DIR}/*.la \
 "
+python __anonymous() {
+    bb.warn("distutils-common-base.bbclass is deprecated, please use setuptools3-base.bbclass instead")
+}

meta/classes/distutils3-base.bbclass

@@ -4,3 +4,6 @@ RDEPENDS:${PN} += "${@['', '${PYTHON_PN}-core']['${CLASSOVERRIDE}' == 'class-tar
 
 inherit distutils-common-base python3native python3targetconfig
 
+python __anonymous() {
+    bb.warn("distutils3-base.bbclass is deprecated, please use setuptools3-base.bbclass instead")
+

meta/classes/distutils3.bbclass

@@ -14,6 +14,10 @@ DISTUTILS_PYTHON:class-native = "nativepython3"
 
 DISTUTILS_SETUP_PATH ?= "${S}"
 
+python __anonymous() {
+    bb.warn("distutils3.bbclass is deprecated, please use setuptools3.bbclass instead")
+}
+
 distutils3_do_configure() {
     :
 }