bpo-40939: run autoreconf to fix configure{,.ac} disparity (GH-21152)

diff --git a/configure b/configure
index dc590c2..c51f396 100755
--- a/configure
+++ b/configure
@@ -16806,7 +16806,7 @@
 done
 
 
-SRCDIRS="Parser Parser/pegen Objects Python Modules Modules/_io Programs"
+SRCDIRS="Parser Objects Python Modules Modules/_io Programs"
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for build directories" >&5
 $as_echo_n "checking for build directories... " >&6; }
 for dir in $SRCDIRS; do