Drop python2 from bindep.txt

IPA dropped support for Python2 long ago,
and now Python2 is not even available in newer distros,
breaking installation if IPA binary dependencies.

Depends-On: https://review.opendev.org/c/openstack/ironic/+/848345
Change-Id: I75a618f94de58f6de2bd96b37de1894bb0e61998

bindep.txt

@@ -1,7 +1,5 @@
 # these are needed to compile Python dependencies from sources
-python-dev [platform:dpkg test]
 python3-all-dev [platform:dpkg !platform:ubuntu-precise test]
-python-devel [platform:rpm test]
 python3-devel [platform:rpm test]
 build-essential [platform:dpkg test]
 libssl-dev [platform:dpkg test]
@@ -25,7 +23,7 @@ libguestfs [platform:rpm imagebuild]
 python-guestfs [platform:dpkg imagebuild]
 # for TinyIPA build
 wget [imagebuild]
-python-pip [imagebuild]
+python3-pip [imagebuild]
 unzip [imagebuild]
 sudo [imagebuild]
 gawk [imagebuild]