component/zodbtools: remove profiles for ZODB4* tests on python3

ZODB4 does not support python3

component/zodbtools/test-zodb4-py2.cfg

@@ -2,5 +2,8 @@
 
 [buildout]
 extends =
-  test-zodb4.cfg
+  test-common.cfg
   test-py2.cfg
+
+[ZODB]
+major = 4

component/zodbtools/test-zodb4-wc2-py2.cfg

@@ -2,5 +2,8 @@
 
 [buildout]
 extends =
-  test-zodb4-wc2.cfg
+  test-common.cfg
   test-py2.cfg
+
+[ZODB]
+major = 4-wc2

component/zodbtools/test-zodb4-wc2.cfg

-# SlapOS software release to test zodbtools/ZODB4-wc2-py3 on Nexedi testing infrastructure.
-
-[buildout]
-extends = test-common.cfg
-
-[ZODB]
-major = 4-wc2

component/zodbtools/test-zodb4.cfg

-# SlapOS software release to test zodbtools/ZODB4-py3 on Nexedi testing infrastructure.
-
-[buildout]
-extends = test-common.cfg
-
-[ZODB]
-major = 4