tests: fix typo in comment (after v9.1.1511)

related: #17660

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index b1ffd19..f97c432 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -180,7 +180,7 @@
 
 
 " Prepare for calling test_garbagecollect_now().
-" Also avois some delays in Insert mode completion.
+" Also avoids some delays in Insert mode completion.
 let v:testing = 1
 
 " By default, copy each buffer line into allocated memory, so that valgrind can