configure.ac: migrate from python2 to python3

VTY and CTRL tests pass fine with python3. Drop the python2 requirement,
so we can use debian 12 in CI. Some of the files in openbsc/contrib
probably still need python2, but since this is a legacy project we
probably don't care.

Related: OS#5950
Change-Id: I052c59dcc21b8e1dd4a3460cf8af9ccbeed6de5b
---
M openbsc/configure.ac
1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/openbsc/configure.ac b/openbsc/configure.ac
index c5d7a3a..2a864c5 100644
--- a/openbsc/configure.ac
+++ b/openbsc/configure.ac
@@ -198,9 +198,9 @@
 				[Include the VTY/CTRL tests in make check [default=no]]),
 		[enable_ext_tests="$enableval"],[enable_ext_tests="no"])
 if test "x$enable_ext_tests" = "xyes" ; then
-	AC_CHECK_PROG(PYTHON2_AVAIL,python2,yes)
-	if test "x$PYTHON2_AVAIL" != "xyes" ; then
-		AC_MSG_ERROR([Please install python2 to run the VTY/CTRL tests.])
+	AC_CHECK_PROG(PYTHON3_AVAIL,python3,yes)
+	if test "x$PYTHON3_AVAIL" != "xyes" ; then
+		AC_MSG_ERROR([Please install python3 to run the VTY/CTRL tests.])
 	fi
 	AC_CHECK_PROG(OSMOTESTEXT_CHECK,osmotestvty.py,yes)
 	 if test "x$OSMOTESTEXT_CHECK" != "xyes" ; then

