patch 9.1.1318: tests: test_format fails

Problem:  tests: test_format fails (after 9.1.1314).
Solution: Increase the string size.  Add missing test_format.res in
          NEW_TESTS_RES (zeertzjq).

closes: #17144

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 55434b0..de4e30f 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -434,6 +434,7 @@
 	test_float_func.res \
 	test_fnameescape.res \
 	test_fold.res \
+	test_format.res \
 	test_functions.res \
 	test_function_lists.res \
 	test_getcwd.res \