bpo-36508: python-config don't export LINKFORSHARED (GH-12661) (GH-12748)

python-config --ldflags no longer includes flags of the LINKFORSHARED
variable. The LINKFORSHARED variable must only be used to build
executables.
(cherry picked from commit e65f01f78d7bda3013fc5be485afa87ff56511d9)

Co-authored-by: Victor Stinner <vstinner@redhat.com>
diff --git a/Misc/python-config.sh.in b/Misc/python-config.sh.in
index d1d3275..a3c479c 100644
--- a/Misc/python-config.sh.in
+++ b/Misc/python-config.sh.in
@@ -44,7 +44,6 @@
 LIBS="-lpython${VERSION}${ABIFLAGS} @LIBS@ $SYSLIBS"
 BASECFLAGS="@BASECFLAGS@"
 LDLIBRARY="@LDLIBRARY@"
-LINKFORSHARED="@LINKFORSHARED@"
 OPT="@OPT@"
 PY_ENABLE_SHARED="@PY_ENABLE_SHARED@"
 LDVERSION="@LDVERSION@"
@@ -89,15 +88,11 @@
             echo "$LIBS"
         ;;
         --ldflags)
-            LINKFORSHAREDUSED=
-            if [ -z "$PYTHONFRAMEWORK" ] ; then
-                LINKFORSHAREDUSED=$LINKFORSHARED
-            fi
             LIBPLUSED=
             if [ "$PY_ENABLE_SHARED" = "0" ] ; then
                 LIBPLUSED="-L$LIBPL"
             fi
-            echo "$LIBPLUSED -L$libdir $LIBS $LINKFORSHAREDUSED"
+            echo "$LIBPLUSED -L$libdir $LIBS"
         ;;
         --extension-suffix)
             echo "$SO"