[libxml2] Remove Makefile rule to build testapi.c

[Nick Wellnhofer <nwellnhof src gnome org>]

commit b60cdf1f9a98a851383b951cd72e89a76aff500b
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Thu Aug 18 19:17:37 2022 +0200

    Remove Makefile rule to build testapi.c
    
    This file is under version control and should only be rebuilt on
    demand.

 Makefile.am | 8 --------
 1 file changed, 8 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index cb1a0757..eaa9a7a7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -135,14 +135,6 @@ rebuild_testapi:
        -@(if [ "$(PYTHON)" != "" ] ; then \
            $(PYTHON) $(srcdir)/gentest.py $(srcdir) ; fi )
 
-# that one is just to make sure it is rebuilt if missing
-# but adding the dependances generate mess
-testapi.c: $(srcdir)/gentest.py
-       -@(if [ "$(PYTHON)" != "" ] ; then \
-           $(PYTHON) $(srcdir)/gentest.py $(srcdir) ; fi )
-
-BUILT_SOURCES = testapi.c
-
 testapi_SOURCES=testapi.c
 testapi_LDFLAGS = 
 testapi_DEPENDENCIES = $(DEPS)